Early assembly of the most massive galaxies

Chris A. Collins; John P. Stott; Matt Hilton; Scott T. Kay; S. Adam Stanford; Michael Davidson; Mark Hosmer; Ben Hoyle; Andrew Liddle; Ed Lloyd-Davies; Robert G. Mann; Nicola Mehrtens; Christopher J. Miller; Robert C. Nichol; A. Kathy Romer; Martin Sahlén; Pedro T. P. Viana; Michael J. West

doi:10.1038/nature07865

Early assembly of the most massive galaxies

Chris A. Collins, John P. Stott, Matt Hilton, Scott T. Kay, S. Adam Stanford, Michael Davidson, Mark Hosmer, Ben Hoyle, Andrew Liddle, Ed Lloyd-Davies, Robert G. Mann, Nicola Mehrtens, Christopher J. Miller, Robert C. Nichol, A. Kathy Romer, Martin Sahlén, Pedro T. P. Viana, Michael J. West

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract / Description of output

The current consensus is that galaxies begin as small density fluctuations in the early Universe and grow by in situ star formation and hierarchical merging. Stars begin to form relatively quickly in sub-galactic-sized building blocks called haloes which are subsequently assembled into galaxies. However, exactly when this assembly takes place is a matter of some debate. Here we report that the stellar masses of brightest cluster galaxies, which are the most luminous objects emitting stellar light, some 9 billion years ago are not significantly different from their stellar masses today. Brightest cluster galaxies are almost fully assembled 4-5 billion years after the Big Bang, having grown to more than 90 per cent of their final stellar mass by this time. Our data conflict with the most recent galaxy formation models based on the largest simulations of dark-matter halo development. These models predict protracted formation of brightest cluster galaxies over a Hubble time, with only 22 per cent of the stellar mass assembled at the epoch probed by our sample. Our findings suggest a new picture in which brightest cluster galaxies experience an early period of rapid growth rather than prolonged hierarchical assembly.

Original language	English
Pages (from-to)	603-606
Journal	Nature
Volume	458
DOIs	https://doi.org/10.1038/nature07865
Publication status	Published - 2 Apr 2009

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10.1038/nature07865

http://adsabs.harvard.edu/abs/2009Natur.458..603C

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@article{111680295ee94ee6b32f3941ccdb6845,

title = "Early assembly of the most massive galaxies",

abstract = "The current consensus is that galaxies begin as small density fluctuations in the early Universe and grow by in situ star formation and hierarchical merging. Stars begin to form relatively quickly in sub-galactic-sized building blocks called haloes which are subsequently assembled into galaxies. However, exactly when this assembly takes place is a matter of some debate. Here we report that the stellar masses of brightest cluster galaxies, which are the most luminous objects emitting stellar light, some 9 billion years ago are not significantly different from their stellar masses today. Brightest cluster galaxies are almost fully assembled 4-5 billion years after the Big Bang, having grown to more than 90 per cent of their final stellar mass by this time. Our data conflict with the most recent galaxy formation models based on the largest simulations of dark-matter halo development. These models predict protracted formation of brightest cluster galaxies over a Hubble time, with only 22 per cent of the stellar mass assembled at the epoch probed by our sample. Our findings suggest a new picture in which brightest cluster galaxies experience an early period of rapid growth rather than prolonged hierarchical assembly.",

author = "Collins, {Chris A.} and Stott, {John P.} and Matt Hilton and Kay, {Scott T.} and Stanford, {S. Adam} and Michael Davidson and Mark Hosmer and Ben Hoyle and Andrew Liddle and Ed Lloyd-Davies and Mann, {Robert G.} and Nicola Mehrtens and Miller, {Christopher J.} and Nichol, {Robert C.} and Romer, {A. Kathy} and Martin Sahl{\'e}n and Viana, {Pedro T. P.} and West, {Michael J.}",

year = "2009",

month = apr,

day = "2",

doi = "10.1038/nature07865",

language = "English",

volume = "458",

pages = "603--606",

journal = "Nature",

issn = "1476-4687",

publisher = "Nature Publishing Group",

}

TY - JOUR

T1 - Early assembly of the most massive galaxies

AU - Collins, Chris A.

AU - Stott, John P.

AU - Hilton, Matt

AU - Kay, Scott T.

AU - Stanford, S. Adam

AU - Davidson, Michael

AU - Hosmer, Mark

AU - Hoyle, Ben

AU - Liddle, Andrew

AU - Lloyd-Davies, Ed

AU - Mann, Robert G.

AU - Mehrtens, Nicola

AU - Miller, Christopher J.

AU - Nichol, Robert C.

AU - Romer, A. Kathy

AU - Sahlén, Martin

AU - Viana, Pedro T. P.

AU - West, Michael J.

PY - 2009/4/2

Y1 - 2009/4/2

N2 - The current consensus is that galaxies begin as small density fluctuations in the early Universe and grow by in situ star formation and hierarchical merging. Stars begin to form relatively quickly in sub-galactic-sized building blocks called haloes which are subsequently assembled into galaxies. However, exactly when this assembly takes place is a matter of some debate. Here we report that the stellar masses of brightest cluster galaxies, which are the most luminous objects emitting stellar light, some 9 billion years ago are not significantly different from their stellar masses today. Brightest cluster galaxies are almost fully assembled 4-5 billion years after the Big Bang, having grown to more than 90 per cent of their final stellar mass by this time. Our data conflict with the most recent galaxy formation models based on the largest simulations of dark-matter halo development. These models predict protracted formation of brightest cluster galaxies over a Hubble time, with only 22 per cent of the stellar mass assembled at the epoch probed by our sample. Our findings suggest a new picture in which brightest cluster galaxies experience an early period of rapid growth rather than prolonged hierarchical assembly.

AB - The current consensus is that galaxies begin as small density fluctuations in the early Universe and grow by in situ star formation and hierarchical merging. Stars begin to form relatively quickly in sub-galactic-sized building blocks called haloes which are subsequently assembled into galaxies. However, exactly when this assembly takes place is a matter of some debate. Here we report that the stellar masses of brightest cluster galaxies, which are the most luminous objects emitting stellar light, some 9 billion years ago are not significantly different from their stellar masses today. Brightest cluster galaxies are almost fully assembled 4-5 billion years after the Big Bang, having grown to more than 90 per cent of their final stellar mass by this time. Our data conflict with the most recent galaxy formation models based on the largest simulations of dark-matter halo development. These models predict protracted formation of brightest cluster galaxies over a Hubble time, with only 22 per cent of the stellar mass assembled at the epoch probed by our sample. Our findings suggest a new picture in which brightest cluster galaxies experience an early period of rapid growth rather than prolonged hierarchical assembly.

U2 - 10.1038/nature07865

DO - 10.1038/nature07865

M3 - Article

SN - 1476-4687

VL - 458

SP - 603

EP - 606

JO - Nature

JF - Nature

ER -

Early assembly of the most massive galaxies

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