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NGC 7479, Caldwell 44, Pegasus, Propeller Galaxy
NGC7479 is a distorted barred spiral galaxy in the constellation of Pegasus, discovered by W. Herschel in 1784. With apparent diameter of 4.4 arcmin, and apparent magnitude of 10.85 (V), visual observation calls for large apertures. However, its basic structures are evident photographically with modest telescopes. From its measurable properties we can derive light travel distance (lookback time) of 110 million light years, redshift recession velocity of 2,379 km/s, actual diameter of 140,000 ly, and absolute magnitude of -21.83 (V), approximately 1.5 times as bright as the Milky Way. NGC7479 has an active galactic nucleus (AGN) which is 8.5 times brighter in the near IR (z filter) than in the visible band, and which emits narrow spectral lines of weakly ionized elements. These characteristics classify it as a Seyfert 2 and a LINER galaxy. It is powered by an actively accreting central supermassive black hole (SMBH) obscured by a large, dense cloud of light-absobing gas and dust. The nucleus is also active at radio frequencies, suggesting the SMBH has polar jets emitting synchrotron radiation. Bright blue floccules in the spiral arms and even within the bar are OB Associations, or vast clusters of recently formed blue giant stars which emit most of their energy in the ultraviolet band. NGC7479 is an isolated field galaxy with no nearby neighbors. Starburst activity, several stellar streams, and gravitational distortion in the W spiral arm are thought to have been caused by a merger with one or more dwarf satellite galaxies between 300 and 100 million years ago.
As the annotated image illustrates, different spectral bands reveal different details within a galaxy. In the ultraviolet band (GALEX), the most prominent features are OB associations, starburst regions, and reflection nebulae. The compact, round UV signal overlapping the N arm of the bar may be the remnant nucleus of a merged dwarf galaxy. The NGC7479 nucleus is not prominent because it is surrounded by a thick layer of gas and dust which absorb and scatter predominantly UV light. However, the brightest feature on the infrared (2MASS) image of the galaxy is precisely the main galactic nucleus with a central SMBH, because longer wavelengths are less obsured. The bulge and the bar are also distinctive due to the presence of ancient cool and red Population II stars. Radio frequency imaging of the galaxy reveals the presence of a bright jet-like feature, centered on the nucleus, and extending through the bar about 20,000 light years in the N and in the S direction. The jet's spiral morphology mildly curves in the direction opposite to that of the stellar and gaseous spiral arms, suggesting that the two structures may be counter-rotating. Jet bending can be caused by precession of the central SMBH accretion disk, by the presence of a binary central SMBH, and/or an off center merger with another galaxy. Based on the rate of expansion and the maximum distance from the nucleus, the jet is felt to be less than 10 million years old.
A large galaxy cluster is visible in the remote background at an estimated light travel distance of 1.5 to 2 billion light years. Only two of these have assigned identifiers. Their measurable and derived properties are listed in the chart on the annotated image.
Image details:
-Remote Takahashi TOA 150 x 1105 mm, Paramount GT GEM,
-OSC 34 x 300 sec, 2x drizzle, 50% linear crop,
-Software: DSS, XnView, StarNet++ v2, StarTools v1.3 and 1.7, Cosmological Calculator v3
The incredibly distant galaxy GS-z13-1, observed just 330 million years after the Big Bang, was initially discovered with deep imaging from the NASA/ESA/CSA James Webb Space Telescope. Now, an international team of astronomers has definitively identified powerful hydrogen emission from this galaxy at an unexpectedly early period in the Universe’s history, a probable sign that we are seeing some of the first hot stars from the dawn of the Universe.
This image shows the location of the galaxy GS-z13-1 in the GOODS-S field, as well as the galaxy itself, imaged with Webb’s Near-Infrared Camera (NIRCam) as part of the JWST Advanced Deep Extragalactic Survey (JADES) programme. These data from NIRCam allowed researchers to identify GS-z13-1 as an incredibly distant galaxy, and to put an estimate on its redshift value. Webb’s unique infrared sensitivity is necessary to observe galaxies at this extreme distance, whose light has been redshifted into infrared wavelengths during its long journey across the cosmos.
To confirm the galaxy’s redshift, the team turned to Webb’s Near-Infrared Spectrograph (NIRSpec) instrument. With new observations permitting advanced spectroscopy of the galaxy’s emitted light, the team not only confirmed GS-z13-1’s redshift of 13.0, they also revealed the strong presence of a type of ultraviolet radiation called Lyman-α emission. This is a telltale sign of the presence of newly forming stars, or a possible active galactic nucleus in the galaxy, but at a much earlier time than astronomers had thought possible. The result holds great implications for our understanding of the Universe.
[Image description: An area of deep space is covered by a scattering of galaxies in many shapes and in colours ranging from blue to whitish to orange, as well as a few nearby stars. A very small square is shown zoomed in, in a box to the left. In the centre a red dot, a faraway galaxy, is marked out by lines and labelled 'Redshift (z)=13', signifying its extreme distance. Two much larger galaxies are labelled 'z=0.63' and 'z=0.70'. The box is titled 'JADES-GS-z13-1'.]
Credits: ESA/Webb, NASA, STScI, CSA, JADES Collaboration, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA), J. Witstok, P. Jakobsen, A. Pagan (STScI), M. Zamani (ESA/Webb; CC BY 4.0
Dusty, peculiar spiral galaxy with apparently only one arm, if it can be considered an arm. One wonders if the apparent disk shape is true or merely a line-of-sight illusion. Clustered texture to the stars indicates a lot of star formation is probably going on.
Another one from Prop 15446. Couldn't find an appropriate color source for this one. DSS was about it, and that wouldn't be much better than completely artificial color. V* TW Hor, a fairly bright star, lies about 4.75' northwest (off the bottom of this frame) from the galaxy, further complicating the use of survey data.
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is 106.03° clockwise from up.
Better resolution: nicolasillustrations.com/project/ngc7497-lrgb
NGC 7497 is a barred spiral galaxy located in the constellation Pegasus. Its velocity relative to the cosmic microwave background corresponds to a Hubble distance of 19.8 ± 1.4 Mpc (approximately 64.6 million light-years). Discovered by the German-British astronomer William Herschel in 1784, it was also observed by the British astronomer John Herschel in 1825.
NGC 7497 has a luminosity class of VI and a broad HI line. With a surface brightness of 14.38 mag/arcsec², it is categorized as a low surface brightness galaxy (LSB), where LSB galaxies, of diffuse (D) type, have a surface brightness at least one magnitude fainter than the ambient night sky.
Currently, twenty-two non-redshift-based measurements indicate a distance of 17.864 ± 3.715 Mpc (approximately 58.3 million light-years), which is consistent with Hubble distance values.
During visual observations, this spiral galaxy appears as a faint grayish bar. However, on extended photographic exposures, a different spectacle unfolds. The accumulation of photons reveals that NGC 7497 is, in reality, "captured" in an extensive molecular cloud named LBN 419, listed in Lynds' Catalog of Bright Nebulae, which includes 1791 bright nebulae. Molecular clouds are celestial regions where gas and dust conglomerate, primarily composed of molecular hydrogen (H2). These cold regions also serve as stellar nurseries, where new stars are born. It's worth noting that LBN 419 is actually much closer, located within our own galaxy.
RA 23h 08m 58.9s
DEC +11° 11' 37.2"
SIZE 30.5 x 20.1 arcmin
ORIENTATION Up is 184.4 degrees E of N
CONSTELLATION Pegasus
MAGNITUDE 12.2
DISTANCE 64 million ly
Captured July 2023
Technical Details
Data acquisition: Telescope.Live
Processing: Nicolas ROLLAND
Location: El Sauce Observatory, Rio Hurtado, CHILE
L: 32*300s
R: 32*300s
G: 35*300s
B: 32*300s
Optics: PLANEWAVE CDK24 @ F/6.5
Mount: Mathis MI-1000/1250 with absolute encoders
CCD: QHY 600M Pro
Astrodon LRGB 2GEN
They seem close to evenly matched. Interestingly, both seem to have some brighter spots that could potentially be considered a place where most of the mass is, but I am unable to discern a nucleus for either one.
Data from the following proposal is used to create this image:
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is 26.1° counter-clockwise from up.
Stephan's Quintet, (HCG 92, Arp 319), NGC 7320 Galaxy Group, Pegasus
This tight visual grouping of five galaxies was discovered in 1877 by Edouard Stephan at the Marseilles Observatory with the revolutionary 80 cm Foucault reflector, which was among the first to use a mirror of silvered glass, instead of speculum metal. The Quintet is the first compact group of galaxies ever documented. It has been carefully studied by numerous observatories ever since because it shows three galaxies in the process of merging, NGC7318-A, NGC7318-B, and NGC7319. All three appear to be barred spiral galaxies, severely distorted by tidal interactions. All display elongated and disrupted spiral arms, faint tidal tails of stars and gas drawn out from the galaxies into intergalactic space, and numerous bright blue regions of countless new stars ignited by gravitational perturbations of hydrogen clouds. Hubble's multi-band images in visible and infrared light reveal stellar populations of several age groups, indicating that starburst activity occurred in different epochs over hundreds of millions of years. In the long run, after billions of years, the three galaxies are destined to merge into a single giant elliptical galaxy. Based on their redshifts, and assuming Hubble Flow, the three galaxies lie at light travel distances between 267 and 312 million light years. However, they are probably much closer together. Due to strong gravitational interaction, they must have high peculiar velocities through space, which renders their distance estimates based on Hubble Flow unreliable.
www.cloudynights.com/articles/cat/articles/basic-extragal...
The fourth galaxy in the group is a modest elliptical galaxy, NGC 7317, gravitationally bound to its companions, but so far morphologically unaffected. These four galaxies are also gravitationally bound to the distant members of the Deer Lick Group, from which they are separated by only 35 arcmin.
www.cloudynights.com/topic/802766-ngc-7331-deer-lick-gala...
The most prominent galaxy in Stephan's Quintet is NGC 7320, a bright dwarf unbarred spiral which is actually 8 times closer than the other members of the visual grouping, and is gravitationally unbound to them. Based on its measurable properties (redshift, apparent magnitude, and angular size), it lies at a light travel distance of 36.4 Mly, receding at 706 km/s due to Hubble Flow (the expansion of space). Its diameter is only about 25,000 ly, five times smaller than the Milky Way's, and absolute magnitude some twenty times fainter. Blue color indicates a high star formation rate and a profusion of large, young, and very hot stars.
The most distant galaxy in the field is 2MFGC 17021, a large edge-on spiral, approximately the same size as the Milky Way, but about twice as bright. It is 784 Mly distant, receding at 17,113 km/s.
Image Details:
-Remote Takahashi TOA 150 x 1105 mm
-Paramount GT GEM
-25 x 300 sec subs, OSC, 2x drizzle, 30% linear crop
-Software: DSS, XnView, StarTools v 1.3 and 1.7, Cosmological Calculator v 2
Messier 64, M64, NGC 4826 Coma Berenices, The Black Eye Galaxy
M64 is a weakly-barred spiral galaxy in Coma Berenices discovered by Pigott in 1779, and independently by Messier in 1780. It is distinctive for a dark band of light-absorbing dust around a bright nucleus, an outer ring-like structure, and an inner ring structure with tightly bound spiral arms. The galaxy has a Seyfert II type of active galactic nucleus which is bright in the infrared band, displays narrow emission line spectrum of weakly ionized gas, and is a weak source of radio waves. The nucleus is powered by a central supermassive black hole. The interstellar gas and dust medium studied at radio frequencies reveals two counter-rotating rings suggesting a possible merger with a smaller gas-rich galaxy. Doppler shifts of stars within the galaxy manifest no such counter-rotation.
Based on its measurable properties (redshift, angular size , and apparent magnitude), we can calculate M64 diameter to be 58,000 ly and absolute magnitude -20.27, approximately half the values of the Milky Way. Its light travel distance (lookback time) is 18.64 million ly, and redshift based recession velocity 402 km/s.
Four transient events have been recorded within M64. One was an optical event, marked on the annotated image with X, and three were SPRITES (eSPecially Red Intermediate Luminosity Transient Events) marked with S, detected in the mid-infrared band without optical counterparts. Transient events are typically brighter than novae and fainter than supernovae, but their duration is much shorter, measured in days. The cause of transient events is not conclusively known. Possible mechanisms include star collisions, massive WR star ejections, "failed supernovae", and brief "nonthermal" synchrotron emissions from intermediate-mass black holes. www.cloudynights.com/articles/cat/articles/transient-opti...
The field is strewn with very distant galaxies, most of which have no identifier. The identified ones seem to cluster in two groups at distances around 960 Mly and 1.4 Bly.
The image also includes four quasars, two of which are receding faster than the speed of light in the present cosmological epoch. They have crossed the cosmic event horizon, and the light they are presently emitting can never reach us. 2XMM J125627.9+215406 (Z = 1.87234) redshift or relativistic recession velocity was 234,974 km/s when the light was emitted nearly 10.2 billion years ago. As the Universe expanded, the object's distance and recession velocity also increased. In the present epoch, the quasar's calculated comoving or proper distance is 16.366 billion ly, and its proper recession velocity is superluminal at 353,685 km/s. The most distant object is quasar SDSS J125613.79+214018.1 (z = 2.082), at the very threshold of the limiting magnitude. Its light travel distance is 10.52 billion ly, proper distance 17.42 billion ly, and proper recession velocity superluminal at 376,359 km/s. With absolute magnitude of -28.26, this quasar is nearly a thousand times brighter than our entire galaxy.
Image details:
TSAPO100Q telescope, Sigma APO 1.4X tele-extender, 100x812 mm
Canon T3i modified camera, Astronomik L3 filter
iEQ30pro mount, Orion SSAGpro 60mm f/4 autoguider
32 x 240 sec subexposures, iso 1600, 30 darks, 30 bias frames, 2x drizzle, 50% linear crop
Software: PHD2, DSS, XnView, StarNet++ v2, StarTools v1.3 and 1.7, Cosmological Calculator v2
Nothing can travel faster than the speed of light - 1 billion kilometer per hour - not even quasars. To know more about quasars see the animation below ...
Digitally altered in Photoshop from this photo kindly provided by Patrick Boury pbo31.
Field Galaxy NGC 2903, Satellite Galaxy UGC 5086, and Four Quasars, Leo
NGC 2903 is a barred spiral galaxy in the constellation of Leo, first documented by William Herschel in 1784. Although it is bright and fairly large, easily seen in binoculars, it escaped the attention of Charles Messier and his associate Pierre Mechain. On a large scale, NGC 2903 lies within the Virgo Supercluster which includes the Milky Way and Andromeda galaxies. Except for dwarf elliptical galaxy UGC 5086, at a distance of 2 million ly, it has no nearby neighbors, and does not belong to any local galaxy cluster. Such isolated galaxies, undisturbed by gravitational fields of large neighbors, are called "field galaxies", constitute 10-20% of the total galaxy population, and follow different evolutionary pathways than "cluster galaxies". Unaffected by major tidal forces and mergers, large field galaxies are most commonly low-surface-brightness (LSB) spirals with delicate and symmetrical spiral arm structure, and usually manifest low star formation rates (SFR). However, NGC 2903 is far from quiescent. Although its energy output is insufficient to qualify it as an active galactic nucleus (AGN), its nucleus is still bright in all bands, from radio waves to X-rays, suggesting the presence of a central supermassive black hole (SMBH) with polar jets and an accretion disk. Photometric and spectroscopic analysis of the central region reveals increased star formation rates generated by interstellar medium turbulence initiated by radiation pressure and feedback outflows from the central SMBH. The turbulence then extends outward, augmented by stellar winds and supernovae, enhancing new star formation further afield. The distinct blue floccules in the spiral arms represent "OB associations", huge clusters of very hot young stars.
www.cloudynights.com/articles/cat/articles/basic-extragal...
From its measurable properties, using the redshift-independent distance method, it can be calculated that NGC 2903 is about 24 million ly distant, and 98,000 light years in diameter, roughly 30% smaller than the Milky Way, and proportionally less luminous. Several interesting features within the galaxy are marked on the annotated image. Some sources define object NGC 2905 as a bright region south of the nucleus. Opinions differ whether the object is a large collection of stars or a very hot ionized hydrogen (Hii) region. Meanwhile, both NED and SIMBAD extragalactic databases list NGC 2905 simply as a duplicate identifier for the main galaxy. Along the NE perimeter of the galaxy, marked with "S" on the annotated chart, there is evidence of a curved luminous region which does not seem to be a part of the spiral arm. I speculate it may be a small satellite galaxy in the process of merging, stretched into a "stellar stream" by the tidal forces of the main galaxy. Computer models show that stellar streams can persist for billions of years through multiple galactic orbits before they are ultimately dispersed into anonymity. Gaps in stellar streams are thought to be caused by encounters with dark matter overdensities (subhalos) within the galactic halo. In the west quadrant of the galaxy, marked with letter "x" on the annotated image", are located two ultra-luminous X-ray sources (ULX). Such objects can be associated with intermediate-mass black holes (IMBH), and may emit optical transients during the periods of more active accretion.
www.cloudynights.com/articles/cat/articles/basic-extragal...
Numerous distant galaxies are visible in the background, many of which have no identifier. Of the more prominent ones, the most formidable is SDSS J093239.53+214555.7, a hyperluminous giant galaxy, at least 160,000 ly in diameter, lying at a distance around 3.2 billion ly. Near the threshold of the limiting magnitude can be seen four quasars (QSOs) listed in the chart below. The most luminous one is QSO B0929+2128, nearly 2,500 times brighter than the Miky Way.The most remote is QSO B0929+218 whose light travelled 11.1 billion years before reching us. When its photons were emitted, the quasar was receding at 255,249 km/s from the past location of our Galaxy (relativistic or redshift recession velocity). In the present epoch, it lies at a "comoving = proper distance" of 19.4 billion ly, receding at a superluminal "proper recession velocity" of 416,815 km/s. The quasar is now located well beyond the "cosmic event horizon". Since the space between us is expanding faster than its light is moving toward us, the photons it is presently emitting can never reach us.
Image details:
-Remote Takahashi TOA 150 x 1105mm, Paramount GT GEM
-27 x 300 sec subs, OSC, 2x drizzle, 60% linear crop
-Software: DSS, XnView, StarNet++ v2, StarTools v 1.3 and 1.8
The Redshift Star Fighter 's ultra-sensitive spacial array is used to quickly lock the rail gun onto phase shifting enemies.
The incredibly distant galaxy GS-z13-1, observed just 330 million years after the Big Bang, was initially discovered with deep imaging from the NASA/ESA/CSA James Webb Space Telescope. Now, an international team of astronomers has definitively identified powerful hydrogen emission from this galaxy at an unexpectedly early period in the Universe’s history, a probable sign that we are seeing some of the first hot stars from the dawn of the Universe.
This image shows the location of the galaxy GS-z13-1 in the GOODS-S field, as well as the galaxy itself, imaged with Webb’s Near-Infrared Camera (NIRCam) as part of the JWST Advanced Deep Extragalactic Survey (JADES) programme. These data from NIRCam allowed researchers to identify GS-z13-1 as an incredibly distant galaxy, and to put an estimate on its redshift value. Webb’s unique infrared sensitivity is necessary to observe galaxies at this extreme distance, whose light has been redshifted into infrared wavelengths during its long journey across the cosmos.
To confirm the galaxy’s redshift, the team turned to Webb’s Near-Infrared Spectrograph (NIRSpec) instrument. With new observations permitting advanced spectroscopy of the galaxy’s emitted light, the team not only confirmed GS-z13-1’s redshift of 13.0, they also revealed the strong presence of a type of ultraviolet radiation called Lyman-α emission. This is a telltale sign of the presence of newly forming stars, or a possible active galactic nucleus in the galaxy, but at a much earlier time than astronomers had thought possible. The result holds great implications for our understanding of the Universe.
[Image description: An area of deep space is covered by a scattering of galaxies in many shapes and in colours ranging from blue to whitish to orange, as well as a few nearby stars. A very small square is shown zoomed in, in a box to the left. In the centre a red dot, a faraway galaxy, is the featured galaxy JADES-GS-z13-1.]
Credits: ESA/Webb, NASA, STScI, CSA, JADES Collaboration, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA), J. Witstok, P. Jakobsen, A. Pagan (STScI), M. Zamani (ESA/Webb; CC BY 4.0
✰ This photo was featured on The Epic Global Showcase here: flavoredtape.com/post/155887905474
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aspenexcel:
Redshift
Data from the following proposal is used to create this image:
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is 13.46° counter-clockwise from up.
Chaos.
Data from the following proposal is used to create this image:
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is 65.77° clockwise from up.
Model: Amanda Cowles
Photographer: Justin Bonaparte
NGC5907 (NGC5906, UGC09801), Draco, Knife Edge Galaxy, and Five Quasars
NGC 5907 is a large nearly edge-on spiral galaxy, first documented by W. Herschel in 1788. On a large scale it is one of the brightest members of the small NGC5866 Galaxy Group in the constellation of Draco. Although the designation generally refers to the entire galaxy, it was not until 1850 that George Stoney identified the faint W part of the galaxy obscured by prominent equatorial dust lanes as NGC 5906. According to NED (NASA Extragalactic Database), the galaxy is 12.8 arcmin in angular size and 9.18 (V) in integrated apparent magnitude Other values found in the literature for the visible band magnitude include 11.12, 11.8, and 12.46, which simply appear too low when compared to the object's photographic brightness. Due to its edge-on orientation its integrated apparent magnitude and the calculated absolute magnitude are significantly underestimated for two reasons. First, it presents to the observer a much smaller surface area than a face-on galaxy. And second, much of its starlight is absorbed and scattered by thick layers of gas and dust in the galactic plane. Its redshift of 0.002225 indicates light travel distance of 30.88 Mly, assuming redshift is due exclusively to the expansion of space (Hubble Flow). For redshifts < 0.01, redshift-independent distance measurements, such as the Cepheid method, are generally more accurate because a fraction of the redshift value is due to an object's motion through space. For NGC5907 the median redshift-independent distance value is 14.275 Mpc, or 46.54 Mly.
Based on the measurable properties, we can estimate NGC5907 to be 172,000 ly in diameter, approximately 40% larger and two times brighter than the Milky Way. Its redshift indicates a recession velocity of 666 km/s. Its morphological classification is SAc (or Sc), indicating a spiral galaxy with loosely wound arms and no evidence of a nuclear bar. Considering the galaxy's nearly edge-on presentation with 87.2* inclination to our line of sight, the presence of a bar can not be confidently ruled out because a view of the nucleus is obscured by dust, gas, and luminous matter in the galactic disk. Garcia-Burillo et al. (1997) suggest that anomalies in molecular gas kinematics can be explained by the presence of a stellar bar. The galaxy has a thin disk with a nearly absent central bulge, resulting in a bulge-to-disk luminosity ratio of only 0.05. Prominent equatorial dust lanes extend nearly to the edges of the galactic disk. While there is some controversy about the presence of extraplanar dust, Xilouris et al. (1999) report that the thickness of extraplanar dust is about 10% larger than the thickness of the stellar disk. As indicated by the light blue floccules of hot newborn stars and by the presence of numerous ionized hydrogen (Hii) regions in the galactic disk, the galaxy displays an above average star formation rate (SFR). This was initially perplexing since the galaxy was thought to be an isolated field spiral with no evidence of tidal disruption. However, deep-sky images by R Jay GaBany (2006) revealed a complex interweaved structure of stellar debris surrounding the galaxy, resulting from an accretion event over four billion years ago. Gravitational perturbations caused by this stream explain elevated SFR and the slight warp in its galactic disk.
www.cosmotography.com/images/small_ring_ngc5907.html
Although it is statistically very likely that NGC5907 contains a central supermassive black hole (SMBH), literature search reveals no information regarding detection of radio wave or high energy emissions from the galactic nucleus. If a central SMBH is present, it shows no evidence of active accretion at this time. Nor can a central SMBH be confirmed by spectroscopy and stellar kinematics. Due to the edge-on orientation, the nucleus is obscured in the optical band by equatorial gas, dust, and luminous matter.
The annotated image indicates the position of an ultra-luminous X-ray source (ULX) within the galaxy's disk. The precise nature of these objects is not confidently known. In order of probability, their energy source is explained as accretion around an intermediate mass black hole (IMBH), super-Eddington accretion around a neutron star or large stellar-mass black holes (BH), or beamed emissions from high mass X-ray binary stars. Pintore et al. (2018) reported an X-ray transient event in this ULX implying a flux increase by a factor of >35. They find the event is consistent with a ~30 solar mass black hole accreting at the Eddington limit, or with beamed emissions from an accreting neutron star.
Other objects of interest on the annotated image include an irregular dwarf galaxy LEDA 54419. Its redshift is very similar to that of NGC5907 suggesting the two might be bound. Distinct blue color indicating high SFR further increases the possibility of tidal interaction. Unfortunately, no redshift-independent distance measurements have been made for this galaxy, and their interaction can not be confirmed. A number of remote galaxies lie in the background. Four of these which carry identifiers are located at distances between 1.6 and 1.73 Bly. Another six even more remote galaxy candidates are marked with letter G. The image also includes five identified quasars. Three of these appear brigher than their listed apparent magnitudes. They are marked with the "+" sign on the chart below. Since quasar luminosity depends on its SMBH accretion rate, quasars often manifest variability up to several magnitudes over a period of days to years. The last two quasars on the list have super-luminal recession velocities in the present cosmological epoch. They have crossed the cosmic event horizon, and the light they are presently emitting can never reach us. The most remote of the quasars is SDSS J151538.77+560520.4 at a light travel distance (lookback time) of 10.86 billion light years.
Image details:
-Remote Takahashi TOA 150 x 1105mm, SBIG STF-8300C, Paramount GT GEM
-OSC 32 x 300 sec, 2x drizzle, 50% linear crop
-Software: DSS, XnView, StarNet++ v2, StarTools v1.3 and 1.8, Cosmological Calculator v3
Originally planned on shooting this from a dark site on top of a mountain but my laptop had other plans. Ended up taking this from my driveway instead, but I'm very pleased with the detail I got at just 610mm focal length. There are also a number of [other galaxies in the uncropped pic](i.imgur.com/tQfxUFh.jpg) including one over a billion light years away from us (calculated from redshift). This image was taken with a monochrome camera through filters for luminance (all visible light), red, green, blue, and Hydrogen-alpha (656nm), which were combined into a color image. The Hydrogen-alpha was combined with red (described below) to enhance the hydrogen nebulae in the galaxy (red splotches in the spiral arms). Captured on March 21, 22, 24, and 29th, 2021 from a Bortle 6 zone
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**[Equipment:](i.imgur.com/6T8QNsv.jpg)**
* TPO 6" F/4 Imaging Newtonian
* Orion Sirius EQ-G
* ZWO ASI1600MM-Pro
* Skywatcher Quattro Coma Corrector
* ZWO EFW 8x1.25"/31mm
* Astronomik LRGB+CLS Filters- 31mm
* Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
* Agena 50mm Deluxe Straight-Through Guide Scope
* ZWO ASI-120MC for guiding
* Moonlite Autofocuser
**Acquisition:** 10 hours 2 minutes (Camera at Unity Gain, -15°C)
* Lum - 106x120"
* Ha - 30x300"
* Red - 40x120"
* Green - 40x120"
* Blue - 50x120"
* Darks- 30
* Flats- 30 per filter
**Capture Software:**
* Captured using [N.I.N.A.](nighttime-imaging.eu) and PHD2 for guiding and dithering.
**PixInsight Processing:**
* BatchPreProcessing
* StarAlignment
* [Blink](youtu.be/sJeuWZNWImE?t=40)
* ImageIntegration
* DrizzleIntegration (2x, Var β=1.5) (Lum only)
* StarAlign Ha, R, G, B stacks to drizzled L
* DynamicCrop
* DynamicBackgroundExtraction
**Luminance:**
* EZ Decon + Denoise
* ArcsinhStretch + histogramtransformation to bring nonlinear
**RGB:**
* ChannelCombinaiton to combine monochrome R, G, B stacks into color image
* PhotometricColorCalibration
* SCNR green
**Adding Ha:**
> I followed this tutorial which I find produces much better results than my previous NBRGBCombination script technique:
> www.arciereceleste.it/tutorial-pixinsight/cat-tutorial-en...
* PixelMath to make Clean Ha. This effectively isolates just the Ha from the red continuum spectrum
> Ha-Q * (Red-med (Red))
> Q=1.0416
* PixelMath to combine Clean Ha
* PixelMath to add Ha to RGB image ($T)
> R= $T+B*(Ha_Clean - med(Ha_Clean))
> G= $T
> B= $T+B*0.2*(Ha_Clean - med(Ha_Clean))
> B=3
**HaRGB:**
* Slight SCNR
* HSV Repair
* ArcsinhStretch + histogramtransformation to bring nonlinear
* ColorSaturation to slightly desaturate Ha regions
* HistogramTransformation to further stretch to match lum brightness
**Nonlinear:**
* LRGBCombination with stretched L as luminance
* Several [Curve](i.imgur.com/4L61MPU.png)Transformations to adjust lightness, contrast, colors, saturation, etc.
* MoreSCNR
* ACDNR
* LocalHistogramEqualization
* More Curves
* ColorSaturation to *slightly* desaturate Ha regions
* MMT noise reduction
* EZ StarReduction
* Final Curves
* Resample to 60%
* DynamicCrop to 3555x2000
* Annotation
Lots of umbrella-like arcs of stars encircling this galaxy. These are possibly the result of a smaller, compact galaxy dropping into the larger one and swishing back and forth several times as it is stretched out into a long, complex orbit, or perhaps many orbits. It's not something I will ever claim to understand in great detail.
Data from the following proposal is used to create this image:
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is 18.91° clockwise from up.
ESA’s Euclid will examine visible and infrared light from distant galaxies using two scientific instruments on board. These instruments will measure the accurate position and shapes of galaxies in visible light, and their redshift (from which their distance can be derived) in the infrared light. With these data, scientists can construct a 3D map of the distributions of both the galaxies and the dark matter in the Universe. The map will show how large-scale structure evolved over time, tracing the role of dark energy.
The VISible instrument (VIS) takes very sharp images of galaxies over a much larger fraction of sky than would be possible from the ground. These observations will be used to measure the shapes of over a billion galaxies.
As the name suggests, VIS collects visible light. It is sensitive to wavelengths from green (550 nanometres) up to near infrared (900 nm). The instrument uses a mosaic of 36 CCDs (Charge Coupled Devices, a type of camera sensor), each of which contains more than 4000 pixels by 4000 pixels. This gives the detector a total of about 600 megapixels, equivalent to almost seventy 4K resolution screens.
Near-Infrared Spectrometer and Photometer (NISP) is dedicated to making spectroscopic measurements of galaxies, which involves determining how much light they emit per wavelength. This is useful for measuring the galaxies’ redshift, which cosmologists can use to estimate the distance to each galaxy. NISP has the largest field of view for an infrared instrument ever flown in space. The instrument measures near-infrared light (900–2000 nm) using a grid of 16 detectors, each containing more than 2000 by 2000 pixels.
Euclid is ESA’s space telescope designed to explore the dark Universe. The mission will create the largest, most accurate 3D map of the Universe ever produced across 10 billion years of cosmic time. Euclid will explore how the Universe has expanded and how large-scale structure is distributed across space and time, revealing more about the role of gravity and the nature of dark energy and dark matter.
Credits: ESA (acknowledgement: work performed by ATG under contract to ESA), CC BY-SA 3.0 IGO
Data from the following proposal is used to create this image:
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is 1.81° clockwise from up.
NGC 4535, Virgo, The Lost Galaxy of Copeland, and Five Quasars
NGC 4535 is a low surface brightness (LSB) barred spiral galaxy in the constellation Virgo, first documented by William Herschel in 1785. Due to its hazy and "ghostly" visual presentation prominent amateur astronomer Leland Copeland named it "The Lost Galaxy" in the 1950s. Based on its median redshift-independent distance measurement of 51.53 Mly, apparent magnitude of 10.32 (g), and angular size of 7.80 arcmin, the galaxy is approximately 116,000 ly in diameter and 90% as bright as the Milky Way. Its redshift of 0.00657 corresponds to a recession velocity of 1,963 km/s, which is in part due to the expansion of space, and in part to its "peculiar velocity" through space relative to us. Its morphological classification is SAB(s)c, indicating an intermediate-barred spiral galaxy without a central ring, and with moderately wound spiral arms. The galaxy is one of the larger members of the Virgo Galaxy Cluster that includes up to 2,000 members. Like most "cluster spirals" it shows evidence of tidal interaction with other members in the form of spiral arm deformation and splitting, gas depletion, and low average star formation rate (SFR) in the current cosmological epoch. The blue floccules in the spiral structure represent "OB Associations", immense clusters of large and very hot young stars. However, unlike in similar galaxies, these are present in relatively low numbers due to gas depletion in the galactic disk. For this reason, NGC 4535 is regarded as a low surface brightness (LSB) galaxy. A number of curved, elongated structures in the disk strongly resemble "stellar streams", or gravitationally stretched remnants of merged dwarf galaxies. Many major galaxies in the Virgo Cluster show evidence of rapid mass assembly through the process of dwarf galaxy accretion.
NGC 4535 has been extensively investigated regarding the presence of a central supermassive black hole (SMBH). Central black holes have been detected in virtually all substantial galaxies studied. Spectroscopic analysis of the central region in the optical band shows evidence of numerous ionized hydrogen (Hii) clouds. These originate from molecular gas clouds ionized by the powerful ultraviolet radiation emanating either from an SMBH accretion disk and/or circumnuclear regions of new star formation. The width of the spectral lines indicates the "velocity dispersion" of luminous matter near the nucleus, which in turn depends on the intensity of the gravitational field generated by the mass in the galactic center. Studies of NGC 4535 refined the understanding of the relationship between the mass and activity of the central SMBH and the evolution of the galaxy within which it resides. For example, this galaxy's gas depletion and current low average star formation rate are in part due to the return of mass momentum and energy from the black hole to the galaxy by the mechanisms of "SMBH outflows" and "radiation pressure" respectively. These processes expel gas and dust from the galaxy, and are explained in more detail in section 40 here:
www.cloudynights.com/articles/cat/articles/basic-extragal...
While NGC 4535 does not have a central starburst ring structure visible in the optical band, it has been one of the major subjects in recent studies on galactic ring formation (Jiayi Sun et al. 2018). Observational evidence reveals a close association between galactic star formation rate (SFR), molecular gas clouds which are the gas reservoir for star formation, and ionized hydrogen (Hii) regions formed when molecular gas is exposed to ionizing ultraviolet radiation from newborn stars. The hydrogen molecule, H2, originating from the big bang, is by far the main component of molecular gas. The second most abundant component is the carbon monoxide molecule, CO, whose constituent atoms were formed during the preceding generations of "stellar nucleosynthesis". Its emission line at the wavelength of 2.6 mm is used in radio-astronomy to map the distribution of galactic molecular gas clouds. While low mass galaxies show faint and scattered CO emissions, massive spiral galaxies exhibit bright, contiguous ring-like emissions within the galactic bulge (Hughes et al. 2013a). These structures, named "Resonance Rings", are thought to accumulate in regions where the outward acting-forces on the molecules balance the centrally-acting gravitational forces. More precisely, resonance rings form where the kinetic energy of gas molecules, defined by the average "velocity dispersion", balances the gravitational potential energy. The evolution of molecular resonance rings also depends on other mechanisms, such as magnetic fields, central SMBH outflows and radiation pressure, and external gravitational effects and matter exchange related to merging or interacting galaxies. In NGC 4535, a resonance ring was detected approximately 1,500 ly from the center. Under favorable circumstances molecular resonance rings evolve into star-forming regions, and eventually become brightly luminous in the visible band.
Derived properties of identified faint objects are listed in the chart on the annotated image. The most remote are five quasars, four of which lie beyond the "cosmic event horizon", as their recession velocities in the present cosmological epoch are superluminal. Two of them, marked with (+) appear significantly brighter than their listed apparent magnitudes. Many quasars are variable up to several magnitudes with periods ranging from days to years, depending on the inflow of matter available for accretion. The most intrinsically luminous object is LBQS 1232+0815, which is nearly 5,000 times brighter than the Milky Way. The most distant quasar is SDSS J123352.16+080527.4 (z = 2.76700), lying at a light travel distance (lookback time) of 11.33 Bly.
Image details:
-Remote Takahashi TOA 150 x 1105 mm
-OSC 36 x 300 sec, (2021 + 2022), 2x drizzle, 40% linear crop, FOV 31x21 arcmin
-Software: DSS, XnView, Starnet++ v2, StarTools 1.3 and 1.8, Cosmological Calculator 3
One of the last of the galaxies I haven't done yet for this proposal. I've been putting it off because it's not as interesting as most of the others. I'm not sure why it was chosen for the survey. Maybe the ever-so-slight spiral structure it might have?
Establishing HST's Low Redshift Archive of Interacting Systems
All Channels: ACS/WFC F606W
North is 56.46° counter-clockwise from up.
Release Date: March 10, 2010 - Distant galaxy clusters mysteriously stream at a million miles per hour along a path roughly centered on the southern constellations Centaurus and Hydra. A new study led by Alexander Kashlinsky at NASA's Goddard Space Flight Center in Greenbelt, Md., tracks this collective motion -- dubbed the "dark flow" -- to twice the distance originally reported, out to more than 2.5 billion light-years.
Abell 1689, redshift 0.181.
Credit: NASA/Goddard Space Flight Center/Scientific Visualization Studio/ESA/L. Bradley/JHU
To learn more go to:
www.nasa.gov/centers/goddard/news/releases/2010/10-023.html
To see other visualizations related to this story go to:
NGC 4725 Coma Berenices, A One-Armed Spiral Galaxy and 7 Quasars
NGC 4725 is a large intermediate spiral galaxy in the constellation of Coma Berenices, first documented by W. Herschel in 1785. It is the brightest, but relatively isolated, member of the Coma I Galaxy Group, that is itself a part of the Virgo Galaxy Supercluster which includes our own Milky Way.
Its morphological classification is SAB (r)ab pec, indicating a weakly barred, tightly wound spiral galaxy with a complete ring. The galaxy was assigned the "peculiar" descriptor for several reasons. The ring structure is not concentric with the galactic nucleus, and displays elliptical motion. Unlike most spiral galaxies, NGC 4725 displays only a single spiral arm. And, its galactic disk is warped relative to the galactic plane. These anomalies are almost certainly due to strong gravitational interaction with the neighboring NGC 4747 (ARP 159), which is even more highly deformed. Further evidence of interaction, and probable mergers with smaller satellites, comes from the densities in the faint outer parts of the galactic disk suggestive of "stellar streams". These are marked with "S" on the annotated image. Bright blue OB Associations within the ring and along the spiral arm indicate a high star formation rate (SFR), also triggered by tidal interaction. The reddish color along the inner NE edge of the ring is due to Ha fluorescence of hydrogen clouds partially ionized by the ultraviolet radiation emanating from the swarm of very hot and massive young stars. These "stellar nurseries" are especially prominent on infrared images taken by the Spitzer Space Telescope. Spectroscopic studies of the central region indicate the presence of an active galactic nucleus (AGN) of the Seyfert 2 type, caused by a central suppermassive black hole. SIMBAD extragalactic database lists several radio sources without optical counterparts that may be due to compact clouds of neutal hydrogen. It also lists two ultra-luminous X-ray sources (ULX) which are thought to be associated with moderately accreting intermediate-mass black holes (IMBH).
Based on measurable data, NGC 4725 lies at a light travel distance (lookback time) of 41.1 Mly. This is based on the median value of 48 redshift-independent distance estimates which span an unusually wide range of nearly 3. From the distance, angular size, and apparent magnitude we can derive the actual diameter of 114,000 ly and an absolute magnitude of -21.06, approximately 1.25 times brighter than the Milky Way. From the redshift, which is due to the expansion of space and the galaxy's "peculiar velocity" through space, we calculate a recession velocity of 1,209 km/s. (See the note at the bottom of the chart).
The other prominent object in the field is NGC 4712, an emission line barred spiral galaxy with a curiously attenuated central region, possibly obscured by dust and gas. It lies in the faraway background at a distance of 203 Mly, and is about 122,000 ly in diameter - approximately the size of the Milky Way, but only half as bright.
The field is strewn with numerous remote galaxies, most of which have no identifier or observation data listed. A number of these peer through the translucent envelope of NGC 4725, and are marked with letter "G" on the annotated image.
The field also includes seven very distant quasars (QSOs) listed in the attached chart. At this time, some are substantially brighter and some fainter than their photometric data indicate. Letter "X" on the annotated image indicates the locations of two fairly bright quasars which have apparently faded beyond the limiting magnitude of approximately 20.5. The last six quasars on the list have superluminal "proper recession velocities" in the present epoch. They have receded beyond the "cosmic event horizon", and the light they are now emitting can never reach us. The last two on the list are "hyperluminous quasars", more than 2,000 times brighter than the entire Milky Way galaxy. SDSS J125125.57+252026.2 is the most distant. The photons we are presently recording have travelled 11.7 billion years (lookback = light travel time). In the present epoch, its "comoving = proper distance" is nearly 22 Bly. Over the next few billion years, its redshift will gradually increase until the quasar becomes forever invisible. From the photons' perspective, travelling at the speed of light time does not pass, and their journey was instantaneous.
See the link for more information on ULX, IMBH and quasars:
www.cloudynights.com/articles/cat/articles/basic-extragal...
-Remote Takahashi TOA 150 x 1105mm
-OSC 36 x 300 sec, 2x drizzle, 50% linear crop
-Software:
DSS, XnView, StarNet++ v2, StarTools
Extragalactic Cosmological Calculator v2
www.cloudynights.com/gallery/image/123530-extragalactic-c...
redshift removals
helping you to come and go
doppler shifts r us
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farnarkling and here we are. This one was tooling along nicely as a mediation on the texture of the filleted avian component of my 'Surfin' Birds' piece. I'd got that more or less to where I wanted to go, but thought that the environment could use a kick of its own to help contrast with the artifact. Mindful of other serendipitous interventions I experimented with the normally mundane "Red-Eye Removal" filter, and...u beaut! A fair bit more digital
The haiku grew out of the "Not An Idle Bone" title as I thought of moving house on a galactic scale, and the "Red" part of "Red-Eye" in a cosmic sense. Christian Doppler, of course, was an Austrian, which as any typographer knows, means he's practically Australian...no worries Herr matey, ta very much!
And it even kinda blips out a little visual pulse from strobing when it scrolls on the screen...wicked! (GRINS) It's rather far out when viewed full screen too.
Taken with my Pentax 67 with 200mm lens and Ilford HP5 Plus film. Scanned with my Plustek OpticFilm 120
Soon after the start of the NASA/ESA/CSA James Webb Space Telescope’s science operations, astronomers noticed something unexpected in the data: red objects that appear small on the sky, located in the distant, young universe. Come to be known as “little red dots” (LRDs), this intriguing class of objects is not well understood at present, sparking new questions and prompting new theories about the processes that occurred in the early universe.
A team of astronomers sifted through James Webb Space Telescope data from multiple surveys to compile one of the largest samples of “little red dots” (LRDs) to date. The team started with the Cosmic Evolution Early Release Science (CEERS) survey before widening their scope to other extragalactic legacy fields, including the JWST Advanced Deep Extragalactic Survey (JADES) and the Next Generation Deep Extragalactic Exploratory Public (NGDEEP) survey.
From their sample, they found that these mysterious red objects that appear small on the sky emerge in large numbers around 600 million years after the big bang and undergo a rapid decline in quantity around 1.5 billion years after the big bang. Spectroscopic data of some of the LRDs in their sample, provided by the Red Unknowns: Bright Infrared Extragalactic Survey (RUBIES), suggests that many are accreting black holes. However, further study of these intriguing objects is required.
[Image description: Six Webb images of little red dots are combined in a two-row mosaic. Each little red dot is centered within a square frame and lies against the black background of space. Each dot has a yellow-white circular core surrounded by a red, fuzzy ring. White text in the top left corner of each box lists the source’s name from the Webb surveys, and its redshift. From left to right, the top row reads CEERS 14448, z = 4.75; NGDEEP 4321, z = 8.92; and PRIMER-COS 10539, z = 7.48. The bottom row reads CEERS 20320, z = 5.27; JADES 9186, z = 4.99; and PRIMER-UDS 17818, z = 6.40.]
Credits: NASA, ESA, CSA, STScI, D. Kocevski (Colby College); CC BY 4.0
We'd trade away the sky if we thought it would save us.
Data from the following proposal is used to create this image:
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is 17.62° counter-clockwise from up.