We investigate the evolution of the star formation rate (SFR)-density relation in the Extended Chandra Deep Field South and the Great Observatories Origin Deep Survey fields up to z ˜ 1.6. In addition to the `traditional method', in which the environment is defined according to a statistical measurement of the local galaxy density, we use a `dynamical' approach, where galaxies are classified according to three different environment regimes: group, `filament-like' and field. Both methods show no evidence of an SFR-density reversal. Moreover, group galaxies show a mean SFR lower than other environments up to z ˜ 1, while at earlier epochs group and field galaxies exhibit consistent levels of star formation (SF) activity. We find that processes related to a massive dark matter halo must be dominant in the suppression of the SF below z ˜ 1, with respect to purely density-related processes. We confirm this finding by studying the distribution of galaxies in different environments with respect to the so-called main sequence (MS) of star-forming galaxies. Galaxies in both group and `filament-like' environments preferentially lie below the MS up to z ˜ 1, with group galaxies exhibiting lower levels of star-forming activity at a given mass. At z > 1, the star-forming galaxies in groups reside on the MS. Groups exhibit the highest fraction of quiescent galaxies up to z ˜ 1, after which group, `filament-like' and field environments have a similar mix of galaxy types. We conclude that groups are the most efficient locus for SF quenching. Thus, a fundamental difference exists between bound and unbound objects, or between dark matter haloes of different masses.

Reversal or no reversal: the evolution of the star formation rate-density relation up to z ˜ 1.6

CIMATTI, ANDREA;POZZI, FRANCESCA;CAPPELLUTI, NICO;
2014

Abstract

We investigate the evolution of the star formation rate (SFR)-density relation in the Extended Chandra Deep Field South and the Great Observatories Origin Deep Survey fields up to z ˜ 1.6. In addition to the `traditional method', in which the environment is defined according to a statistical measurement of the local galaxy density, we use a `dynamical' approach, where galaxies are classified according to three different environment regimes: group, `filament-like' and field. Both methods show no evidence of an SFR-density reversal. Moreover, group galaxies show a mean SFR lower than other environments up to z ˜ 1, while at earlier epochs group and field galaxies exhibit consistent levels of star formation (SF) activity. We find that processes related to a massive dark matter halo must be dominant in the suppression of the SF below z ˜ 1, with respect to purely density-related processes. We confirm this finding by studying the distribution of galaxies in different environments with respect to the so-called main sequence (MS) of star-forming galaxies. Galaxies in both group and `filament-like' environments preferentially lie below the MS up to z ˜ 1, with group galaxies exhibiting lower levels of star-forming activity at a given mass. At z > 1, the star-forming galaxies in groups reside on the MS. Groups exhibit the highest fraction of quiescent galaxies up to z ˜ 1, after which group, `filament-like' and field environments have a similar mix of galaxy types. We conclude that groups are the most efficient locus for SF quenching. Thus, a fundamental difference exists between bound and unbound objects, or between dark matter haloes of different masses.
2014
Ziparo, F.; Popesso, P.; Finoguenov, A.; Biviano, A.; Wuyts, S.; Wilman, D.; Salvato, M.; Tanaka, M.; Nandra, K.; Lutz, D.; Elbaz, D.; Dickinson, M.; Altieri, B.; Aussel, H.; Berta, S.; Cimatti, A.; Fadda, D.; Genzel, R.; Le Floc'h, E.; Magnelli, B.; Nordon, R.; Poglitsch, A.; Pozzi, F.; Portal, M. Sanchez; Tacconi, L.; Bauer, F. E.; Brandt, W. N.; Cappelluti, N.; Cooper, M. C.; Mulchaey, J. S.
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/527361
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 35
  • ???jsp.display-item.citation.isi??? 34
social impact