scholarly journals Redshift measurement through star formation

2019 ◽  
Vol 629 ◽  
pp. A7
Author(s):  
Mikkel O. Lindholmer ◽  
Kevin A. Pimbblet
Keyword(s):  
Star Formation ◽  
Galaxy Clusters ◽  
Main Sequence ◽  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
X Ray ◽  
Star Forming ◽  
Sky Survey ◽  
The Galaxy ◽  
Galaxy Population

In this work we use the property that, on average, star formation rate increases with redshift for objects with the same mass – the so called galaxy main sequence – to measure the redshift of galaxy clusters. We use the fact that the general galaxy population forms both a quenched and a star-forming sequence, and we locate these ridges in the SFR–M⋆ plane with galaxies taken from the Sloan Digital Sky Survey in discrete redshift bins. We fitted the evolution of the galaxy main sequence with redshift using a new method and then subsequently apply our method to a suite of X-ray selected galaxy clusters in an attempt to create a new distance measurement to clusters based on their galaxy main sequence. We demonstrate that although it is possible in several galaxy clusters to measure the main sequences, the derived distance and redshift from our galaxy main sequence fitting technique has an accuracy of σz = ±0.017 ⋅ (z + 1) and is only accurate up to z ≈ 0.2.

scholarly journals A single galaxy population? Statistical evidence that the star-forming main sequence might be the tip of the iceberg

2020 ◽  
Vol 499 (1) ◽  
pp. 573-586
Author(s):  
P Corcho-Caballero ◽  
Y Ascasibar ◽  
Á R López-Sánchez
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Formation Rate ◽  
Current Data ◽  
Point Of View ◽  
Sloan Digital Sky Survey ◽  
Additional Parameter ◽  
Star Forming ◽  
Mass Assembly ◽  
Galaxy Population

ABSTRACT According to their specific star formation rate (sSFR), galaxies are often divided into ‘star-forming’ and ‘passive’ populations. It is argued that the former define a narrow ‘main sequence of star-forming galaxies’ (MSSF) of the form sSFR(M*), whereas ‘passive’ galaxies feature negligible levels of star formation activity. Here we use data from the Sloan Digital Sky Survey and the Galaxy And Mass Assembly survey at z < 0.1 to constrain the conditional probability of the sSFR at a given stellar mass. We show that the whole population of galaxies in the local Universe is consistent with a simple probability distribution with only one maximum (roughly corresponding to the MSSF) and relatively shallow power-law tails that fully account for the ‘passive’ population. We compare the quality of the fits provided by such unimodal ansatz against those coming from a double lognormal fit (illustrating the bimodal paradigm), finding that both descriptions are roughly equally compatible with the current data. In addition, we study the physical interpretation of the bidimensional distribution across the M*–sSFR plane and discuss potential implications from a theoretical and observational point of view. We also investigate correlations with metallicity, morphology, and environment, highlighting the need to consider at least an additional parameter in order to fully specify the physical state of a galaxy.

scholarly journals Searching for Mg ii absorbers in and around galaxy clusters

2021 ◽  
Vol 503 (3) ◽  
pp. 4309-4319
Author(s):  
Jong Chul Lee ◽  
Ho Seong Hwang ◽  
Hyunmi Song
Keyword(s):  
Galaxy Clusters ◽  
Detection Rate ◽  
Massive Star ◽  
Sloan Digital Sky Survey ◽  
Number Density ◽  
Cluster Galaxies ◽  
Star Forming ◽  
Quasar Spectra ◽  
Sky Survey ◽  
The Galaxy

ABSTRACT To study environmental effects on the circumgalactic medium (CGM), we use the samples of redMaPPer galaxy clusters, background quasars, and cluster galaxies from the Sloan Digital Sky Survey (SDSS). With ∼82 000 quasar spectra, we detect 197 Mg ii absorbers in and around the clusters. The detection rate per quasar is 2.7 ± 0.7 times higher inside the clusters than outside the clusters, indicating that Mg ii absorbers are relatively abundant in clusters. However, when considering the galaxy number density, the absorber-to-galaxy ratio is rather low inside the clusters. If we assume that Mg ii absorbers are mainly contributed by the CGM of massive star-forming galaxies, a typical halo size of cluster galaxies is smaller than that of field galaxies by 30 ± 10 per cent. This finding supports that galaxy haloes can be truncated by interaction with the host cluster.

scholarly journals xGASS: the role of bulges along and across the local star-forming main sequence

2020 ◽  
Vol 493 (4) ◽  
pp. 5596-5605 ◽  
Author(s):  
Robin H W Cook ◽  
Luca Cortese ◽  
Barbara Catinella ◽  
Aaron Robotham
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Formation Rate ◽  
Stellar Mass ◽  
Local Universe ◽  
Star Forming ◽  
Star Formation Activity ◽  
The Galaxy ◽  
Stellar Masses

ABSTRACT We use our catalogue of structural decomposition measurements for the extended GALEX Arecibo SDSS Survey (xGASS) to study the role of bulges both along and across the galaxy star-forming main sequence (SFMS). We show that the slope in the sSFR–M⋆ relation flattens by ∼0.1 dex per decade in M⋆ when re-normalizing specifice star formation rate (sSFR) by disc stellar mass instead of total stellar mass. However, recasting the sSFR–M⋆ relation into the framework of only disc-specific quantities shows that a residual trend remains against disc stellar mass with equivalent slope and comparable scatter to that of the total galaxy relation. This suggests that the residual declining slope of the SFMS is intrinsic to the disc components of galaxies. We further investigate the distribution of bulge-to-total ratios (B/T) as a function of distance from the SFMS (ΔSFRMS). At all stellar masses, the average B/T of local galaxies decreases monotonically with increasing ΔSFRMS. Contrary to previous works, we find that the upper envelope of the SFMS is not dominated by objects with a significant bulge component. This rules out a scenario in which, in the local Universe, objects with increased star formation activity are simultaneously experiencing a significant bulge growth. We suggest that much of the discrepancies between different works studying the role of bulges originate from differences in the methodology of structurally decomposing galaxies.

scholarly journals What is Important? Morphological Asymmetries are Useful Predictors of Star Formation Rates of Star-forming Galaxies in SDSS Stripe 82

2021 ◽  
Vol 923 (2) ◽  
pp. 205
Author(s):  
Hassen M. Yesuf ◽  
Luis C. Ho ◽  
S. M. Faber
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
Imaging Data ◽  
Galaxy Interactions ◽  
Star Forming ◽  
Sky Survey ◽  
Structural Variables ◽  
Central Concentration

Abstract The morphology and structure of galaxies reflect their star formation and assembly histories. We use the framework of mutual information (MI) to quantify the interdependence among several structural variables and to rank them according to their relevance for predicting the specific star formation rate (SSFR) by comparing the MI of the predictor variables with the SSFR and penalizing variables that are redundant. We apply this framework to study ∼3700 face-on star-forming galaxies (SFGs) with varying degrees of bulge dominance and central concentration and with stellar mass M ⋆ ≈ 109 M ⊙−5 × 1011 M ⊙ at redshift z = 0.02–0.12. We use the Sloan Digital Sky Survey (SDSS) Stripe 82 deep i-band imaging data, which improve measurements of asymmetry and bulge dominance indicators. We find that star-forming galaxies are a multiparameter family. In addition to M ⋆, asymmetry emerges as the most powerful predictor of SSFR residuals of SFGs, followed by bulge prominence/concentration. Star-forming galaxies with higher asymmetry and stronger bulges have higher SSFR at a given M ⋆. The asymmetry reflects both irregular spiral arms and lopsidedness in seemingly isolated SFGs and structural perturbations by galaxy interactions or mergers.

scholarly journals Deep learning for galaxy mergers in the galaxy main sequence

2019 ◽  
Vol 15 (S341) ◽  
pp. 104-108
Author(s):  
William J. Pearson ◽  
Lingyu Wang ◽  
James Trayford ◽  
Carlo E. Petrillo ◽  
Floris F. S. van der Tak
Keyword(s):  
Deep Learning ◽  
Star Formation ◽  
Main Sequence ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Stellar Mass ◽  
Galaxy Mergers ◽  
The Galaxy ◽  
Galaxy Population ◽  
Stellar Masses

AbstractStarburst galaxies are often found to be the result of galaxy mergers. As a result, galaxy mergers are often believed to lie above the galaxy main sequence: the tight correlation between stellar mass and star formation rate. Here, we aim to test this claim.Deep learning techniques are applied to images from the Sloan Digital Sky Survey to provide visual-like classifications for over 340 000 objects between redshifts of 0.005 and 0.1. The aim of this classification is to split the galaxy population into merger and non-merger systems and we are currently achieving an accuracy of 92.5%. Stellar masses and star formation rates are also estimated using panchromatic data for the entire galaxy population. With these preliminary data, the mergers are placed onto the full galaxy main sequence, where we find that merging systems lie across the entire star formation rate - stellar mass plane.

scholarly journals Star formation in CALIFA early-type galaxies: a matter of discs

2019 ◽  
Vol 488 (1) ◽  
pp. L80-L84 ◽  
Author(s):  
J Méndez-Abreu ◽  
S F Sánchez ◽  
A de Lorenzo-Cáceres
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Formation Rate ◽  
Molecular Gas ◽  
Early Type ◽  
Star Forming ◽  
Integral Field Spectroscopy ◽  
The Galaxy ◽  
First Time ◽  
Integral Field

ABSTRACT The star formation main sequence (SFMS) is a tight relation between the galaxy star formation rate (SFR) and its total stellar mass (M⋆). Early-type galaxies (ETGs) are often considered as low-SFR outliers of this relation. We study, for the first time, the separated distribution in the SFR versus M⋆ of bulges and discs of 49 ETGs from the CALIFA survey. This is achieved using c2d, a new code to perform spectrophotometric decompositions of integral field spectroscopy data cubes. Our results reflect that: (i) star formation always occurs in the disc component and not in bulges; (ii) star-forming discs in our ETGs are compatible with the SFMS defined by star-forming galaxies at z ∼ 0; (iii) the star formation is not confined to the outskirts of discs, but it is present at all radii (even where the bulge dominates the light); (iv) for a given mass, bulges exhibit lower sSFR than discs at all radii; and (v) we do not find a deficit of molecular gas in bulges with respect to discs for a given mass in our ETGs. We speculate our results favour a morphological quenching scenario for ETGs.

scholarly journals Galaxy pairs in the Sloan Digital Sky Survey – XIV. Galaxy mergers do not lie on the fundamental metallicity relation

2020 ◽  
Vol 494 (3) ◽  
pp. 3469-3480 ◽  
Author(s):  
Sebastián Bustamante ◽  
Sara L Ellison ◽  
David R Patton ◽  
Martin Sparre
Keyword(s):  
Star Formation ◽  
Gas Phase ◽  
Formation Rate ◽  
Local Environment ◽  
Stellar Mass ◽  
Sloan Digital Sky Survey ◽  
Galaxy Mergers ◽  
Star Forming ◽  
Sky Survey ◽  
Evolutionary Phase

ABSTRACT In recent observational studies, star-forming galaxies have been shown to follow a relation often dubbed the fundamental metallicity relation (FMR). This relation links the stellar mass of a galaxy with its star formation rate (SFR) and its gas-phase metallicity. Specifically, the FMR predicts that galaxies, at a given stellar mass, exhibit lower metallicities for higher SFRs. This trend is qualitatively consistent with observations of galaxy pairs, which have been robustly shown to experience increasing gas-phase metallicity dilution and enhanced star formation activity with decreasing projected separation. In this work, we show that, despite the qualitative consistency with FMR expectations, the observed O/H dilution in galaxy pairs of the Sloan Digital Sky Survey is stronger than what is predicted by the FMR. We conclude that the evolutionary phase of galaxies interacting with companions is not encoded in the FMR, and thus, mergers constitute a clearly defined population of outliers. We find that galaxies in pairs are consistent with the FMR only when their separation is larger than 110 kpc. Finally, we also quantify the local environment of the pairs using the number of galaxy neighbours within 2 Mpc, N2, and the projected separation to the second closest galaxy, r2. We find that pairs are more sensitive to a second companion than to the local galaxy density, displaying less elevated SFRs with smaller values of r2.

scholarly journals Galaxy Population in the Infall Regions of Intermediate Redshift Clusters

2006 ◽  
Vol 2 (S235) ◽  
pp. 254-254
Author(s):  
Miguel Verdugo ◽  
Bodo L. Ziegler
Keyword(s):  
Star Formation ◽  
X Ray ◽  
Cluster Galaxies ◽  
Star Forming ◽  
Star Formation Activity ◽  
The Galaxy ◽  
Galaxy Populations ◽  
Cluster Cores ◽  
Galaxy Population ◽  
Special Environment

AbstractWe investigate the galaxy populations in 6 clusters of different x-ray luminosities at intermediate redshifts (z ≈ 0.25) concentrating on their star formation activity. Our ~500 Calar Alto MOSCA spectra come from targets covering large fields out to 2–4 cluster virial radii. To probe this so-called infall region is important since here newly arriving galaxies from the surrounding field encounter the special environment of clusters for the first time. We selected 3 fields containing 2 clusters each from the X-ray Dark Cluster Survey (Gilbank et al. 2004). Results for one field were already published by Gerken et al. 2004.We find evidence that the process(es) that suppresses or truncates the star formation activity in cluster galaxies, sets in already at rather large distances from the cluster cores corresponding to low projected local galaxy densities. This changes the fraction of star forming galaxies rather quickly.

scholarly journals The star formation activity of IllustrisTNG galaxies: main sequence, UVJ diagram, quenched fractions, and systematics

2019 ◽  
Vol 485 (4) ◽  
pp. 4817-4840 ◽  
Author(s):  
Martina Donnari ◽  
Annalisa Pillepich ◽  
Dylan Nelson ◽  
Mark Vogelsberger ◽  
Shy Genel ◽  
...  
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Formation Rate ◽  
Stellar Mass ◽  
Star Forming ◽  
Systematic Uncertainties ◽  
The Galaxy ◽  
Hydrodynamical Simulations ◽  
Averaging Time ◽  
Stellar Masses

Abstract We select galaxies from the IllustrisTNG hydrodynamical simulations ($M_{\rm stars}\gt 10^9 \, {\rm M}_\odot$ at 0 ≤ z ≤ 2) and characterize the shapes and evolutions of their UVJ and star formation rate–stellar mass (SFR–Mstars) diagrams. We quantify the systematic uncertainties related to different criteria to classify star-forming versus quiescent galaxies, different SFR estimates, and by accounting for the star formation measured within different physical apertures. The TNG model returns the observed features of the UVJ diagram at z ≤ 2, with a clear separation between two classes of galaxies. It also returns a tight star-forming main sequence (MS) for $M_{\rm stars}\lt 10^{10.5} \, ({\rm M}_\odot)$ with a ∼0.3 dex scatter at z ∼ 0 in our fiducial choices. If a UVJ-based cut is adopted, the TNG MS exhibits a downwardly bending at stellar masses of about 1010.5−10.7 M⊙. Moreover, the model predicts that ${\sim }80\, (50)$ per cent of 1010.5−11 M⊙ galaxies at z = 0 (z = 2) are quiescent and the numbers of quenched galaxies at intermediate redshifts and high masses are in better agreement with observational estimates than previous models. However, shorter SFR-averaging time-scales imply higher normalizations and scatter of the MS, while smaller apertures lead to underestimating the galaxy SFRs: overall we estimate the inspected systematic uncertainties to sum up to about 0.2−0.3 dex in the locus of the MS and to about 15 percentage points in the fraction of quenched galaxies. While TNG colour distributions are clearly bimodal, this is not the case for the SFR logarithmic distributions in bins of stellar mass (SFR ≳ 10−3 M⊙yr−1). Finally, the slope and z = 0 normalization of the TNG MS are consistent with observational findings; however, the locus of the TNG MS remains lower by about 0.2−0.5 dex at 0.75 ≤ z < 2 than the available observational estimates taken at face value.

Tracing young SMBHs in the dusty distant universe – a Chandra view of DOGs

2020 ◽  
Vol 15 (S359) ◽  
pp. 17-21
Author(s):  
Karín Menéndez-Delmestre ◽  
Laurie Riguccini ◽  
Ezequiel Treister
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Far Infrared ◽  
Host Galaxy ◽  
X Ray ◽  
Star Forming ◽  
Near Ir ◽  
X Ray Imaging ◽  
Combined Use ◽  
Dusty Galaxies

AbstractThe coexistence of star formation and AGN activity has geared much attention to dusty galaxies at high redshifts, in the interest of understanding the origin of the Magorrian relation observed locally, where the mass of the stellar bulk in a galaxy appears to be tied to the mass of the underlying supermassive black hole. We exploit the combined use of far-infrared (IR) Herschel data and deep Chandra ˜160 ksec depth X-ray imaging of the COSMOS field to probe for AGN signatures in a large sample of >100 Dust-Obscured Galaxies (DOGs). Only a handful (˜20%) present individual X-ray detections pointing to the presence of significant AGN activity, while X-ray stacking analysis on the X-ray undetected DOGs points to a mix between AGN activity and star formation. Together, they are typically found on the main sequence of star-forming galaxies or below it, suggesting that they are either still undergoing significant build up of the stellar bulk or have started quenching. We find only ˜30% (6) Compton-thick AGN candidates (NH > 1024 cm–2), which is the same frequency found within other soft- and hard-X-ray selected AGN populations. This suggests that the large column densities responsible for the obscuration in Compton-thick AGNs must be nuclear and have little to do with the dust obscuration of the host galaxy. We find that DOGs identified to have an AGN share similar near-IR and mid-to-far-IR colors, independently of whether they are individually detected or not in the X-ray. The main difference between the X-ray detected and the X-ray undetected populations appears to be in their redshift distributions, with the X-ray undetected ones being typically found at larger distances. This strongly underlines the critical need for multiwavelength studies in order to obtain a more complete census of the obscured AGN population out to higher redshifts. For more details, we refer the reader to Riguccini et al. (2019).

Sign in / Sign up

Export Citation Format

Share Document