scholarly journals Characterizing the abundance, properties, and kinematics of the cool circumgalactic medium of galaxies in absorption with SDSS DR16

2021 ◽  
Vol 504 (1) ◽  
pp. 65-88
Author(s):  
Abhijeet Anand ◽  
Dylan Nelson ◽  
Guinevere Kauffmann
Keyword(s):  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
Gas Absorption ◽  
Dark Matter Halo ◽  
Star Forming ◽  
Sky Survey ◽  
Optical Continuum ◽  
Circumgalactic Medium ◽  
Emission Line Galaxies ◽  
Red Galaxies

ABSTRACT In order to study the circumgalactic medium (CGM) of galaxies we develop an automated pipeline to estimate the optical continuum of quasars and detect intervening metal absorption line systems with a matched kernel convolution technique and adaptive S/N criteria. We process ∼ one million quasars in the latest Data Release 16 (DR16) of the Sloan Digital Sky Survey (SDSS) and compile a large sample of ∼ 160 000 Mg ii absorbers, together with ∼ 70 000 Fe ii systems, in the redshift range 0.35 < zabs < 2.3. Combining these with the SDSS DR16 spectroscopy of ∼1.1 million luminous red galaxies (LRGs) and ∼200 000 emission line galaxies (ELGs), we investigate the nature of cold gas absorption at 0.5 < z < 1. These large samples allow us to characterize the scale dependence of Mg ii with greater accuracy than in previous work. We find that there is a strong enhancement of Mg ii absorption within ∼50 kpc of ELGs, and the covering fraction within 0.5rvir of ELGs is 2–5 times higher than for LRGs. Beyond 50 kpc, there is a sharp decline in Mg ii for both kinds of galaxies, indicating a transition to the regime where the CGM is tightly linked with the dark matter halo. The Mg ii-covering fraction correlates strongly with stellar mass for LRGs, but weakly for ELGs, where covering fractions increase with star formation rate. Our analysis implies that cool circumgalactic gas has a different physical origin for star-forming versus quiescent galaxies.

scholarly journals Red Misfits in the Sloan Digital Sky Survey: properties of star-forming red galaxies

2018 ◽  
Vol 476 (4) ◽  
pp. 5284-5302 ◽  
Author(s):  
Fraser A Evans ◽  
Laura C Parker ◽  
Ian D Roberts
Keyword(s):  
Sloan Digital Sky Survey ◽  
Star Forming ◽  
Sky Survey ◽  
Red Galaxies

scholarly journals Mg II λ2797, λ2803 emission in a large sample of low-metallicity star-forming galaxies from SDSS DR14

2019 ◽  
Vol 624 ◽  
pp. A21 ◽  
Author(s):  
N. G. Guseva ◽  
Y. I. Izotov ◽  
K. J. Fricke ◽  
C. Henkel
Keyword(s):  
Noble Gas ◽  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
Large Sample ◽  
Star Forming ◽  
Magnesium Depletion ◽  
Sky Survey ◽  
Solar Metallicity ◽  
Low Metallicity ◽  
Damped Lyman Alpha Systems

A large sample of Mg II emitting star-forming galaxies with low metallicity [O/H] = log(O/H) – log(O/H)⊙ between –0.2 and –1.2 dex is constructed from Data Release 14 of the Sloan Digital Sky Survey. We selected 4189 galaxies with Mg II λ2797, λ2803 emission lines in the redshift range z ∼ 0.3–1.0 or 35% of the total Sloan Digital Sky Survey star-forming sample with redshift z ≥ 0.3. We study the dependence of the magnesium-to-oxygen and magnesium-to-neon abundance ratios on metallicity. Extrapolating this dependence to [Mg/Ne] = 0 and to solar metallicity we derive a magnesium depletion of [Mg/Ne] ≃ –0.4 (at solar metallicity). We prefer neon instead of oxygen to evaluate the magnesium depletion in the interstellar medium because neon is a noble gas and is not incorporated into dust, contrary to oxygen. Thus, we find that more massive and more metal abundant galaxies have higher magnesium depletion. The global parameters of our sample, such as the mass of the stellar population and star formation rate, are compared with previously obtained results from the literature. These results confirm that Mg II emission has a nebular origin. Our data for interstellar magnesium-to-oxygen abundance ratios relative to the solar value are in good agreement with similar measurements made for Galactic stars, for giant stars in the Milky Way satellite dwarf galaxies, and with low-metallicity damped Lyman-alpha systems.

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 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 Properties and redshift evolution of star-forming galaxies with high [O III]/[O II] ratios with MUSE at 0.28 < z < 0.85

2018 ◽  
Vol 618 ◽  
pp. A40 ◽  
Author(s):  
M. Paalvast ◽  
A. Verhamme ◽  
L. A. Straka ◽  
J. Brinchmann ◽  
E. C. Herenz ◽  
...  
Keyword(s):  
Formation Rate ◽  
Incidence Rates ◽  
Sloan Digital Sky Survey ◽  
Star Forming ◽  
Sky Survey ◽  
Combining Data ◽  
Low Metallicity ◽  
The Relationship ◽  
Bright Emission ◽  
Similar Incidence

We present a study of the [O III]/[O II] ratios of star-forming galaxies drawn from Multi-Unit Spectroscopic Explorer (MUSE) data spanning a redshift range 0.28 < z < 0.85. Recently discovered Lyman continuum (LyC) emitters have extremely high oxygen line ratios: [O III]λ5007/[O II]λλ3726, 3729 > 4. Here we aim to understand the properties and the occurrences of galaxies with such high line ratios. Combining data from several MUSE Guaranteed Time Observing (GTO) programmes, we select a population of star-forming galaxies with bright emission lines, from which we draw 406 galaxies for our analysis based on their position in the z-dependent star formation rate (SFR)–stellar mass (M∗) plane. Out of this sample 15 are identified as extreme oxygen emitters based on their [O III]/[O II] ratios (3.7%) and 104 galaxies have [O III]/[O II] > 1 (26%). Our analysis shows no significant correlation between M∗, SFR, and the distance from the SFR−M∗ relation with [O III]/[O II]. We find a decrease in the fraction of galaxies with [O III]/[O II] > 1 with increasing M∗, however, this is most likely a result of the relationship between [O III]/[O II] and metallicity, rather than between [O III]/[O II] and M∗. We draw a comparison sample of local analogues with ⟨z⟩ ≈ 0.03 from the Sloan Digital Sky Survey, and find similar incidence rates for this sample. In order to investigate the evolution in the fraction of high [O III]/[O II] emitters with redshift, we bin the sample into three redshift subsamples of equal number, but find no evidence for a dependence on redshift. Furthermore, we compare the observed line ratios with those predicted by nebular models with no LyC escape and find that most of the extreme oxygen emitters can be reproduced by low metallicity models. The remaining galaxies are likely LyC emitter candidates.

scholarly journals The Bimodal Color Distribution of Galaxies at Redshift of z=0-0.15 from the Sloan Digital Sky Survey (SDSS)

2019 ◽  
Vol 30 (2) ◽  
pp. 52
Author(s):  
Hareth Saad Mahdi
Keyword(s):  
Photometric Data ◽  
Sloan Digital Sky Survey ◽  
The Other ◽  
Efficient Tool ◽  
Color Distribution ◽  
Star Forming ◽  
Sky Survey ◽  
Blue Galaxies ◽  
Red Galaxies ◽  
Two Peaks

This work aims to use the color distribution of galaxies to differentiate between blue and red galaxies. The photometric data of 300000 galaxies at redshift of z = 0 – 0.15 were collected from the Sloan Digital Sky Survey (SDSS). Three redshift ranges were considered for the purpose of this work: 100000 galaxies at z = 0-0.05, 100000 galaxies at z = 0.05-0.1 and 100000 galaxies at z = 0.1-0.15. The color distributions for all redshift ranges were determined. The results have clearly shown that the color distributions for all redshift ranges are bimodal. One of the two peaks corresponds to the blue galaxies (young and star-forming galaxies), whereas the other peak corresponds to the red galaxies (old and non-star-forming galaxies). Therefore, the color distribution of galaxies can be considered as an efficient tool to distinguish between blue and red galaxies.

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 Rejuvenation triggers nuclear activity in nearby galaxies

2021 ◽  
Author(s):  
Ignacio Martin Navarro ◽  
Francesco Shankar ◽  
Mar Mezcua
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
Dark Matter Halo ◽  
Sudden Increase ◽  
Star Forming ◽  
Normal Galaxies ◽  
Gas Accretion

Abstract Galaxies, forming and evolving within their host dark matter haloes, are the end-product of a balance between gas cooling, star formation and feedback. Energy/Momentum feedback, in particular from active galactic nuclei (AGN), is believed to play a crucial role in the evolution of galaxies by gradually quenching their star formation. In the local Universe many galaxies with an AGN are indeed observed to reside in the so-called green valley, usually interpreted as a transition phase from a blue star formation epoch to a red quenched state. We use data from the Sloan Digital Sky Survey to show that such an interpretation requires substantial revision. Optically-selected nearby AGN galaxies follow exponentially declining star formation histories, as normal galaxies of similar stellar and dark matter halo mass, reaching in the recent past (~0.1 Gyr ago) star formation rate levels consistent with a quiescent population. However, we find that local AGN galaxies have experienced a sudden increase in their star formation rate, unfolding on timescales similar to those typical of AGN activity, suggesting that both star formation and AGN activity were triggered simultaneously. We find that this quenching process followed by an enhancement in the star formation rate is common to AGN galaxies and more pronounced in early type galaxies. Our results demonstrate that local AGN galaxies are not a transition type between star-forming and quiescent galaxies as previously postulated, but simply galaxies experiencing a recent gas accretion episode.

Sloan Digital Sky Survey Spectroscopic Lens Search. I. Discovery of Intermediate-Redshift Star-forming Galaxies behind Foreground Luminous Red Galaxies

2004 ◽  
Vol 127 (4) ◽  
pp. 1860-1882 ◽  
Author(s):  
Adam S. Bolton ◽  
Scott Burles ◽  
David J. Schlegel ◽  
Daniel J. Eisenstein ◽  
J. Brinkmann
Keyword(s):  
Sloan Digital Sky Survey ◽  
Star Forming ◽  
Luminous Red Galaxies ◽  
Sky Survey ◽  
Red Galaxies ◽  
Intermediate Redshift

scholarly journals The weak imprint of environment on the stellar populations of galaxies

2020 ◽  
Vol 500 (4) ◽  
pp. 4469-4490 ◽  
Author(s):  
James Trussler ◽  
Roberto Maiolino ◽  
Claudia Maraston ◽  
Yingjie Peng ◽  
Daniel Thomas ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Unique Feature ◽  
Stellar Populations ◽  
Stellar Mass ◽  
Sloan Digital Sky Survey ◽  
Star Forming ◽  
Sky Survey ◽  
Satellite Galaxies ◽  
Projected Distance ◽  
Environmental Dependence

ABSTRACT We investigate the environmental dependence of the stellar populations of galaxies in Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Echoing earlier works, we find that satellites are both more metal-rich (&lt;0.1 dex) and older (&lt;2 Gyr) than centrals of the same stellar mass. However, after separating star-forming, green valley, and passive galaxies, we find that the true environmental dependence of both stellar metallicity (&lt;0.03 dex) and age (&lt;0.5 Gyr) is in fact much weaker. We show that the strong environmental effects found when galaxies are not differentiated result from a combination of selection effects brought about by the environmental dependence of the quenched fraction of galaxies, and thus we strongly advocate for the separation of star-forming, green valley, and passive galaxies when the environmental dependence of galaxy properties are investigated. We also study further environmental trends separately for both central and satellite galaxies. We find that star-forming galaxies show no environmental effects, neither for centrals nor for satellites. In contrast, the stellar metallicities of passive and green valley satellites increase weakly (&lt;0.05 and &lt;0.08 dex, respectively) with increasing halo mass, increasing local overdensity and decreasing projected distance from their central; this effect is interpreted in terms of moderate environmental starvation (‘strangulation’) contributing to the quenching of satellite galaxies. Finally, we find a unique feature in the stellar mass–stellar metallicity relation for passive centrals, where galaxies in more massive haloes have larger stellar mass (∼0.1 dex) at constant stellar metallicity; this effect is interpreted in terms of dry merging of passive central galaxies and/or progenitor bias.

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