scholarly journals Tracing the quenching history of cluster galaxies in the EAGLE simulation

2019 ◽  
Vol 488 (1) ◽  
pp. 847-858 ◽  
Author(s):  
Diego Pallero ◽  
Facundo A Gómez ◽  
Nelson D Padilla ◽  
S Torres-Flores ◽  
R Demarco ◽  
...  
Keyword(s):  
Star Formation ◽  
Large Fraction ◽  
Formation Rate ◽  
Direct Consequence ◽  
High Mass ◽  
Cluster Galaxies ◽  
Hydrodynamical Simulation ◽  
Cluster Environment ◽  
History Of ◽  
Low Mass

ABSTRACT We use the Evolution and Assembly of GaLaxies and their Environments (EAGLE) hydrodynamical simulation to trace the quenching history of galaxies in its 10 most massive clusters. We use two criteria to identify moments when galaxies suffer significant changes in their star formation activity: (i) the instantaneous star formation rate (SFR) strongest drop, $\Gamma _{\rm SFR}^{\rm SD}$, and (ii) a ‘quenching’ criterion based on a minimum threshold for the specific SFR of ≲10$^{-11}\,\rm yr^{-1}$. We find that a large fraction of galaxies (${\gtrsim} 60\,{\rm per\,cent}$) suffer their $\Gamma _{\rm SFR}^{\rm SD}$ outside the cluster’s R200. This ‘pre-processed’ population is dominated by galaxies that are either low mass and centrals or inhabit low-mass hosts (1010.5 ≲ Mhost ≲ 1011.0 M⊙). The host mass distribution is bimodal, and galaxies that suffered their $\Gamma _{\rm SFR}^{\rm SD}$ in massive hosts ($10^{13.5} \lesssim M_{\rm host} \lesssim 10^{14.0}\, \mathrm{M}_{\odot }$) are mainly processed within the clusters. Pre-processing mainly limits the total stellar mass with which galaxies arrive in the clusters. Regarding quenching, galaxies preferentially reach this state in high-mass haloes ($10^{13.5} \lesssim M_{\rm host} \lesssim 10^{14.5}\, \mathrm{M}_{\odot }$). The small fraction of galaxies that reach the cluster already quenched have also been pre-processed, linking both criteria as different stages in the quenching process of those galaxies. For the z = 0 satellite populations, we find a sharp rise in the fraction of quenched satellites at the time of first infall, highlighting the role played by the dense cluster environment. Interestingly, the fraction of pre-quenched galaxies rise with final cluster mass. This is a direct consequence of the hierarchical cosmological model used in these simulations.

scholarly journals Properties of simulated galaxies and supermassive black holes in cosmic voids

2020 ◽  
Vol 493 (1) ◽  
pp. 899-921
Author(s):  
Mélanie Habouzit ◽  
Alice Pisani ◽  
Andy Goulding ◽  
Yohan Dubois ◽  
Rachel S Somerville ◽  
...  
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
Star Formation Rate ◽  
Large Fraction ◽  
Formation Rate ◽  
Dark Matter Halo ◽  
Wide Field ◽  
Void Galaxies ◽  
Low Mass ◽  
Cosmic Voids

ABSTRACT Cosmic voids, the underdense regions of the cosmic web, are widely used to constrain cosmology. Voids contain few, isolated galaxies, presumably expected to be less evolved and preserving memory of the pristine Universe. We use the cosmological hydrodynamical simulation Horizon-AGN coupled to the void finder vide to investigate properties of galaxies in voids at z = 0. We find that, closer to void centres, low-mass galaxies are more common than their massive counterparts. At a fixed dark matter halo mass, they have smaller stellar masses than in denser regions. The star formation rate of void galaxies diminishes when approaching void centres, but their specific star formation rate slightly increases, suggesting that void galaxies form stars more efficiently with respect to their stellar mass. We find that this cannot only be attributed to the prevalence of low-mass galaxies. The inner region of voids also predominantly hosts low-mass black holes (BHs). However, the BH mass-to-galaxy mass ratios resemble those of the whole simulation at z = 0. Our results suggest that even if the growth channels in cosmic voids are different from those in denser environments, voids grow their galaxies and BHs in a similar way. While a large fraction of the BHs have low Eddington ratios, we find that $\text{$\sim$} 20{{\ \rm per\ cent}}$ could be observed as active galactic nuclei with $\log _{10} L_{\rm 2\!-\!10 \, keV}=41.5\!-\!42.5 \, \rm erg\, s^{-1}$. These results pave the way to future work with larger next-generation hydro-simulations, aiming to confirm our findings and prepare the application on data from upcoming large surveys such as Prime Focus Spectrograph, Euclid, and Wide Field Infrared Survey Telescope.

scholarly journals Passive spirals and shock influenced star formation in the merging cluster A3376

2020 ◽  
Vol 496 (1) ◽  
pp. 442-455 ◽  
Author(s):  
Kshitija Kelkar ◽  
K S Dwarakanath ◽  
Bianca M Poggianti ◽  
Alessia Moretti ◽  
Rogério Monteiro-Oliveira ◽  
...  
Keyword(s):  
Star Formation ◽  
Rapid Quenching ◽  
Wide Field ◽  
Cluster Galaxies ◽  
Star Forming ◽  
M 10 ◽  
Brightest Cluster Galaxies ◽  
Central Regions ◽  
Cluster Environment ◽  
Low Mass

ABSTRACT We present a detailed analysis of star formation properties of galaxies in a nearby (z ∼ 0.046) young (∼0.6 Gyr) post-merger cluster system A3376, with a moderate merger shock front (vs ∼1630 km s−1; $\mathcal {M}$ ∼ 2) observed as symmetric radio relics. Exploiting the spectroscopic data from the wide-field OmegaWINGS survey and the associated photometric information, our investigations reveal the plausible effects of the dynamic post-merger environment differing from the high-density cluster environment experienced prior to the merging activity. The remnants of the pre-merger relaxed cluster environment are realized through the existence of passive spiral galaxies located in the central regions of the cluster between the two brightest cluster galaxies. We discover A3376 to contain a population of massive (log (M*/M⊙) > 10) blue regular star-forming spirals in regions of maximum merger shock influence but exhibiting star formation rates similar to those in relaxed clusters at similar epoch. We further discover low-mass (log (M*/M⊙) ≤ 10) late-type blue post-starburst galaxies which could either be formed as a result of rapid quenching of low-mass spirals following the shock-induced star formation or due to the intense surge in the intracluster medium pressures at the beginning of the merger. With the possibility of the merger shock affecting high- and low-mass spirals differently, our results bridge the seemingly contradictory results observed in known merging cluster systems so far and establish that different environmental effects are at play right from pre- to post-merger stages.

The Local Group Dwarf Spheroidal Galaxies: A Key to Building Blocks in the Universe

2005 ◽  
Vol 201 ◽  
pp. 469-470
Author(s):  
Hiroyuki. Hirashita ◽  
Naoyuki. Tamura ◽  
Tsutomu T. Takeuchi
Keyword(s):  
Star Formation ◽  
Local Group ◽  
Building Blocks ◽  
Star Formation History ◽  
High Mass ◽  
Dwarf Spheroidal Galaxies ◽  
The Hierarchical Structure ◽  
History Of ◽  
Low Mass ◽  
Spheroidal Galaxies

Recent studies have been revealing the properties of dwarf spheroidal galaxies (dSphs). Their low mass indicates that the dSphs may provide a clue to physical properties of the building blocks in the hierarchical structure formation. We select the Local Group dSphs as a sample. To obtain the information on the star formation history of dSphs, we investigate the relation between their metallicity and virial mass. According to our scenario, the star formation efficiency of the dSphs is low because of strong regulation. This is consistent with their high mass-to-light ratios. We also comment on the environmental effects on the dSphs.

scholarly journals Two Species of Local Group Dwarf Spheroidals

1999 ◽  
Vol 192 ◽  
pp. 451-454
Author(s):  
Tsutomu T. Takeuchi ◽  
Hiroyuki Hirashita
Keyword(s):  
Star Formation ◽  
Local Group ◽  
Star Formation Rate ◽  
Formation Rate ◽  
High Mass ◽  
Dwarf Spheroidal Galaxies ◽  
Total Luminosity ◽  
Virial Mass ◽  
Low Mass ◽  
Quantitative Explanation

We analyzed 10 dwarf spheroidal galaxies (dSphs) in the Local Group, and found two distinct sequences on the Mvir/L - Mvir plane: Mvir/L ∝ Mvir1.6 for Mvir < 108M⊙ whereas Mvir/L ≃ const. for Mvir > 108M⊙ (Mvir and L are the virial mass and the total luminosity of a dSph, respectively). We interpret the discontinuity as the threshold for the gas in dSphs to be blown away by successive supernovae. We succeeded in giving a quantitative explanation of the discontinuity mass of 108M⊙ as the blow-away condition. We further derived the above relation for the low-mass dSphs, assuming that the initial star formation rate of the dSphs is proportional to the inverse of the cooling time. The relation of high-mass dSphs is also explained along with the same consideration, with the condition that the gas cannot be blown away.

scholarly journals Star Formation in Isolated LIRGs: Clues to Star-forming Processes at Higher z

2010 ◽  
Vol 6 (S277) ◽  
pp. 195-198
Author(s):  
Isaura Fuentes-Carrera ◽  
Lorenzo Olguín ◽  
Patricia Ambrocio-Cruz ◽  
Simon Verley ◽  
Margarita Rosado ◽  
...  
Keyword(s):  
Star Formation ◽  
Large Fraction ◽  
Formation Rate ◽  
Local Universe ◽  
Star Forming ◽  
Luminous Infrared Galaxies ◽  
History Of ◽  
Observational Techniques ◽  
Intermediate Redshift ◽  
Very High

AbstractLuminous infrared galaxies (LIRGs) are galaxies with LIR > 1011 L⊙. For a star-forming galaxy to emit at a LIRG level, it must have a very high star formation rate (SFR). In the local Universe, the star formation (SF) is primarily triggered by interactions. However, at intermediate redshift, a large fraction of LIRGs are disk galaxies with little sign of recent merger activity. The question arises whether the intermediate redshift LIRGs are “triggered” or experiencing “normal”, if elevated, SF. Understanding these SF processes is important since this type of systems may have contributed to 20% or more of the cosmic SFR in the early Universe. In order to address this issue we study similar systems in the Local Universe, that is isolated late-type galaxies displaying LIRG activity. We use different observational techniques in order to trace the star-forming history of these systems. Here we present preliminary results.

scholarly journals Sub-galactic scaling relations between X-ray luminosity, star formation rate, and stellar mass

2020 ◽  
Vol 494 (4) ◽  
pp. 5967-5984 ◽  
Author(s):  
K Kouroumpatzakis ◽  
A Zezas ◽  
P Sell ◽  
K Kovlakas ◽  
P Bonfini ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Star Formation History ◽  
High Mass ◽  
X Ray ◽  
Formation History ◽  
Low Mass ◽  
X Ray Binaries ◽  
Intrinsic Scatter

ABSTRACT X-ray luminosity (LX) originating from high-mass X-ray binaries (HMXBs) is tightly correlated with the host galaxy’s star formation rate (SFR). We explore this connection at sub-galactic scales spanning ∼7 dex in SFR and ∼8 dex in specific SFR (sSFR). There is good agreement with established relations down to SFR ≃ 10−3 M$_{\odot }\, \rm {yr^{-1}}$, below which an excess of X-ray luminosity emerges. This excess likely arises from low-mass X-ray binaries. The intrinsic scatter of the LX–SFR relation is constant, not correlated with SFR. Different star formation indicators scale with LX in different ways, and we attribute the differences to the effect of star formation history. The SFR derived from H α shows the tightest correlation with X-ray luminosity because H α emission probes stellar populations with ages similar to HMXB formation time-scales, but the H α-based SFR is reliable only for $\rm sSFR{\gt }10^{-12}$ M$_{\odot }\, \rm {yr^{-1}}$/M⊙.

scholarly journals METALS IN THE ICM: WITNESSES OF CLUSTER FORMATION AND EVOLUTION

2013 ◽  
Vol 53 (A) ◽  
pp. 579-582
Author(s):  
Lorenzo Lovisari ◽  
Tatiana F. Laganá ◽  
Katharina Borm ◽  
Gerrit Schellenberger ◽  
Thomas H. Reiprich
Keyword(s):  
Past History ◽  
Large Fraction ◽  
Cluster Formation ◽  
Direct Consequence ◽  
Cluster Galaxies ◽  
Chemical Enrichment ◽  
History Of ◽  
Formation And Evolution ◽  
The Mean ◽  
Metallicity Distribution

The baryonic composition of galaxy clusters and groups is dominated by a hot, X-ray emitting Intra-Cluster Medium (ICM). The mean metallicity of the ICM has been found to be roughly 0.3 ÷ 0.5 times the solar value, therefore a large fraction of this gas cannot be of purely primordial origin. Indeed, the distribution and amount of metals in the ICM is a direct consequence of the past history of star formation in the cluster galaxies and of the processes responsible for the injection of enriched material into the ICM. We here shortly summarize the current views on the chemical enrichment, focusing on the observational evidence in terms of metallicity measurements in clusters, spatial metallicity distribution and evolution, and expectations from future missions.

scholarly journals H2 content of galaxies inside and around intermediate redshift clusters

2019 ◽  
Vol 15 (S359) ◽  
pp. 158-162
Author(s):  
Damien Spérone-Longin
Keyword(s):  
Star Formation ◽  
Large Fraction ◽  
Formation Rate ◽  
Gas Content ◽  
Cluster Center ◽  
Molecular Gas ◽  
Ample Evidence ◽  
Cluster Galaxies ◽  
Star Forming ◽  
Medium Mass

AbstractDense environments have an impact on the star formation rate of galaxies. As stars form from molecular gas, looking at the cold molecular gas content of a galaxy gives useful insights on its efficiency in forming stars. However, most galaxies observed in CO (a proxy for the cold molecular gas content) at intermediate redshifts, are field galaxies. Only a handful of studies focused on cluster galaxies. I present new results on the environment of one medium mass cluster from the EDisCS survey at z ˜ 0.5. 27 star-forming galaxies were selected to evenly sample the range of densities encountered inside and around the cluster. We cover a region extending as far as 8 virial radii from the cluster center. Indeed there is ample evidence that star formation quenching starts already beyond 3 cluster virial radii. I discuss our CO(3-2) ALMA observations, which unveil a large fraction of galaxies with low gas-to-stellar mass ratios.

scholarly journals Lyman-alpha opacities at z=4-6 require low mass, radiatively-suppressed galaxies to drive cosmic reionization

2021 ◽  
Author(s):  
Pierre Ocvirk ◽  
Joseph S W Lewis ◽  
Nicolas Gillet ◽  
Jonathan Chardin ◽  
Dominique Aubert ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
High Redshift ◽  
Formation Rate ◽  
High Mass ◽  
Lyman Alpha ◽  
Low Mass ◽  
Halo Population ◽  
Fully Coupled ◽  
Two Populations

Abstract The high redshift Lyman-α forest, in particular the Gunn-Peterson trough, is the most unambiguous signature of the neutral to ionized transition of the intergalactic medium (IGM) taking place during the Epoch of Reionization (EoR). Recent studies have shown that reproducing the observed Lyman-α opacity distributions after overlap required a non-monotonous evolution of cosmic emissivity: rising, peaking at z∼6, and then decreasing onwards to z=4. Such an evolution is puzzling considering galaxy buildup and the cosmic star formation rate are still continously on the rise at these epochs. Here, we use new RAMSES-CUDATON simulations to show that such a peaked evolution may occur naturally in a fully coupled radiation-hydrodynamical framework. In our fiducial run, cosmic emissivity at z&gt;6 is dominated by a low mass (${\rm M_{DM}}&lt;2 \times 10^9 \rm M_{\odot }$), high escape fraction halo population, driving reionization, up to overlap. Approaching z=6, this population is radiatively suppressed due to the rising ionizing UV background, and its emissivity drops. In the meantime, the high mass halo population builds up and its emissivity rises, but not fast enough to compensate the dimming of the low mass haloes, because of low escape fractions. The combined ionizing emissivity of these two populations therefore naturally results in a rise and fall of the cosmic emissivity, from z=12 to z=4, with a peak at z∼6. An alternative run, which features higher escape fractions for the high mass haloes and later suppression at low mass, leads to overshooting the ionizing rate, over-ionizing the IGM and therefore too low Lyman-α opacities.

scholarly journals GLACE survey: Galaxy activity in ZwCl0024+1652 cluster from strong optical emission lines

2020 ◽  
Vol 501 (2) ◽  
pp. 2430-2450
Author(s):  
Zeleke Beyoro-Amado ◽  
Miguel Sánchez-Portal ◽  
Ángel Bongiovanni ◽  
Mirjana Pović ◽  
Solomon B Tessema ◽  
...  
Keyword(s):  
Star Formation ◽  
Local Density ◽  
Formation Rate ◽  
Galaxy Cluster ◽  
Optical Emission ◽  
Tunable Filter ◽  
Emission Lines ◽  
High Mass ◽  
Cluster Galaxies ◽  
Emission Line Galaxies

ABSTRACT Although ZwCl0024+1652 galaxy cluster at z ∼ 0.4 has been thoroughly analysed, it lacks a comprehensive study of star formation and nuclear activity of its members. With GaLAxy Cluster Evolution (GLACE) survey, a total of 174 H α emission-line galaxies (ELGs) were detected, most of them having [N ii]. We reduced and analysed a set of [O iii] and H β tunable filter (TF) observations within GLACE survey. Using H α priors, we identified [O iii] and H β in 35 (∼20 per cent) and 59 (∼34 per cent) sources, respectively, with 21 of them having both emission lines, and 20 having in addition [N ii]. Applying BPT-NII diagnostic diagram, we classified these ELGs into 40 per cent star-forming (SF), 55 per cent composites, and 5 per cent LINERs. Star formation rate (SFR) measured through extinction corrected H α fluxes increases with stellar mass (M*), attaining its peak at $\mathrm{\mathit{ M}}_{*}\sim 10^{9.8}\, \mathrm{M}_\odot$. We observed that the cluster centre to ∼ 1.3 Mpc is devoid of SF galaxies and AGN. Our results suggest that the star formation efficiency declines as the local density increases in the cluster medium. Moreover, the SF and AGN fractions drop sharply towards high-density environments. We observed a strong decline in SF fraction in high M*, confirming that star formation is highly suppressed in high-mass cluster galaxies. Finally, we determined that SFR correlates with M* while specific SFR (sSFR) anticorrelates with M*, both for cluster and field. This work shows the importance and strength of TF observations when studying ELGs in clusters at higher redshifts. We provide with this paper a catalogue of ELGs with H β and/or [O iii] lines in ZwCl0024+1652 cluster.

Sign in / Sign up

Export Citation Format

Share Document