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Post Info TOPIC: Spiderweb Galaxy
Blobrana


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RE: Spiderweb Galaxy
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'Shockingly' cold gas cloud surrounding early giant galaxy surprises scientists

The discovery of an enormous reservoir of ultra-cold gas surrounding a distant galaxy has reshaped our scientific understanding of how stars and galaxies formed in the early universe.
An international team of scientists detected the huge halo of gas, 100 billion times the mass of our Sun, surrounding the Spiderweb galaxy, a massive galaxy surrounded by smaller galaxies about 10 billion light-years from Earth.
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Blobrana


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MRC 1138-262
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APEX reveals hidden star formation in protocluster

Astronomers have used the APEX telescope to probe a huge galaxy cluster that is forming in the early Universe and revealed that much of the star formation taking place is not only hidden by dust, but also occurring in unexpected places. This is the first time that a full census of the star formation in such an object has been possible.
Galaxy clusters are the largest objects in the Universe held together by gravity but their formation is not well understood. The Spiderweb Galaxy (formally known as MRC 1138-262) and its surroundings have been studied for twenty years, using ESO and other telescopes, and is thought to be one of the best examples of a protocluster in the process of assembly, more than ten billion years ago.
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Blobrana


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RE: Spiderweb Galaxy
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Title: CO(1-0) detection of molecular gas in the massive Spiderweb Galaxy (z=2)
Authors: B.H.C. Emonts (1), I. Feain (1), H.J.A. Roettgering (2), G. Miley (2), N. Seymour (1), R.P. Norris (1), C.L. Carilli (3), M. Villar-Martin (4), M.Y. Mao (3), E.M. Sadler (5), R.D. Ekers (1), G.A. van Moorsel (3), R.J. Ivison (6,7), L. Pentericci (8), C.N. Tadhunter (9), D.J. Saikia (10,11) ((1) CASS/ATNF, (2) Leiden Obs., (3) NRAO, (4) CAB/INTA-CSIC, (5) Univ. Sydney, (6) UK ATC, (7) Univ. Edinburgh, (8) INAF, (9) Univ. Sheffield, (10) Cotton College State Univ., (11) NCRA/TIFR)

The high-redshift radio galaxy MRC 1138-262 ('Spiderweb Galaxy'; z = 2.16), is one of the most massive systems in the early Universe and surrounded by a dense 'web' of proto-cluster galaxies. Using the Australia Telescope Compact Array, we detected CO(1-0) emission from cold molecular gas -- the raw ingredient for star formation -- across the Spiderweb Galaxy. We infer a molecular gas mass of M(H2) = 6x10^10 solar masses (for M(H2)/L'(CO)=0.8). While the bulk of the molecular gas coincides with the central radio galaxy, there are indications that a substantial fraction of this gas is associated with satellite galaxies or spread across the inter-galactic medium on scales of tens of kpc. In addition, we tentatively detect CO(1-0) in the star-forming proto-cluster galaxy HAE 229, 250 kpc to the west. Our observations are consistent with the fact that the Spiderweb Galaxy is building up its stellar mass through a massive burst of widespread star formation. At maximum star formation efficiency, the molecular gas will be able to sustain the current star formation rate (SFR ~ 1400 solar masses/yr, as traced by Seymour et al.) for about 40 Myr. This is similar to the estimated typical lifetime of a major starburst event in infra-red luminous merger systems.

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Blobrana


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MRC 1138-262
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Title: The growth and assembly of a massive galaxy at z ~ 2
Authors: N.A. Hatch, R.A. Overzier, J.D. Kurk, G.K. Miley, H.J.A. Röttgering, A.W. Zirm

We study the stellar mass assembly of the Spiderweb Galaxy (MRC 1138-262), a massive z = 2.2 radio galaxy in a protocluster and the probable progenitor of a brightest cluster galaxy. Nearby protocluster galaxies are identified and their properties are determined by fitting stellar population models to their rest-frame ultraviolet to optical spectral energy distributions. We find that within 150 kpc of the radio galaxy the stellar mass is centrally concentrated in the radio galaxy, yet most of the dust-uncorrected, instantaneous star formation occurs in the surrounding low-mass satellite galaxies. We predict that most of the galaxies within 150 kpc of the radio galaxy will merge with the central radio galaxy by z = 0, increasing its stellar mass by up to a factor of ~ 2. However, it will take several hundred Myr for the first mergers to occur, by which time the large star formation rates are likely to have exhausted the gas reservoirs in the satellite galaxies. The tidal radii of the satellite galaxies are small, suggesting that stars and gas are being stripped and deposited at distances of tens of kpc from the central radio galaxy. These stripped stars may become intracluster stars or form an extended stellar halo around the radio galaxy, such as those observed around cD galaxies in cluster cores.

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Blobrana


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MRC 1138–262, Spiderweb Galaxy, B1 1138-26
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Images from NASA's Hubble Space Telescope have provided a dramatic glimpse of a large and massive galaxy under assembly by the merging of smaller, lighter galaxies. Astrophysicists believe that this is the way galaxies grew in the young universe. Now, Hubble observations of the radio galaxy MRC 1138-262, nicknamed the "Spiderweb Galaxy" show dozens of star-forming satellite galaxies as individual clumpy features in the process of merging. Because the galaxy is 10.6 billion light-years away, astronomers are seeing it as it looked in the universe's early formative years, only 3 billion years after the Big Bang.

MRC1138262
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Credit NASA

Position (2000): R.A. 11h 40m 48s.4 Dec. -26° 29' 11".0
Constellation: Hydra
Distance: 10.6 billion light-years

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Blobrana


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Spiderweb Galaxy
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New Hubble images have provided a dramatic glimpse of a large massive galaxy under assembly as smaller galaxies merge. This has commonly been thought to be the way galaxies grew in the young Universe, but now Hubble observations of the radio galaxy MRC 1138-262, nicknamed the “Spiderweb Galaxy”, have shown dozens of star-forming satellite galaxies in the actual process of merging.

MRC1138-262
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Credit NASA

In nature spiders earn our respect by constructing fascinating, well-organised webs in all shapes and sizes. But the beauty masks a cruel, fatal trap. Analogously, the NASA/ESA Hubble Space Telescope has found a large galaxy 10.6 billion light-years away from Earth (at a redshift of 2.2) that is stuffing itself with smaller galaxies caught like flies in a web of gravity. The galaxy is so far away that astronomers are seeing it as it looked in the early formative years of the Universe, only 2 billion years after the Big Bang.
The Hubble image shows the Spiderweb Galaxy sitting at the centre of an emergent galaxy cluster, surrounded by hundreds of other galaxies from the cluster.

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