A comparison of the star formation rate and the specific star formation rate distributions between paired galaxies and isolated ones

2013 ◽  
Vol 91 (4) ◽  
pp. 337-342
Author(s):  
Xin-Fa Deng

From each of two volume-limited main galaxy samples of the Sloan Digital Sky Survey data release 7, a paired galaxy sample and an isolated galaxy sample are constructed and comparative studies between the star formation of galaxies in pairs and isolated are performed to explore influences of galaxy interactions on star formation. It is found that isolated galaxies have an enhancement of the star formation rate and the specific star formation rate, which suggests that interactions between galaxies are not the trigger of enhanced star formation.

2013 ◽  
Vol 22 (2) ◽  
Author(s):  
Xin-Fa Deng ◽  
Fuyang Zhang

AbstractFrom the apparent magnitude-limited the Main galaxy sample of the Sloan Digital Sky Survey Data Release 7, we construct a paired galaxy sample and a control sample without close companions with the projected separations


2015 ◽  
Vol 449 (4) ◽  
pp. 3719-3740 ◽  
Author(s):  
Jillian M. Scudder ◽  
Sara L. Ellison ◽  
Emmanuel Momjian ◽  
Jessica L. Rosenberg ◽  
Paul Torrey ◽  
...  

2021 ◽  
Vol 923 (2) ◽  
pp. 205
Author(s):  
Hassen M. Yesuf ◽  
Luis C. Ho ◽  
S. M. Faber

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.


2013 ◽  
Vol 91 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Xin-Fa Deng

The primary goal of this study is to explore the dependence of the clustering properties of galaxies on star formation rate (SFR) and specific star formation rate (SSFR). From the main galaxy sample of the Sloan Digital Sky Survey Data Release 7, we construct two volume-limited samples with absolute magnitudes above and below [Formula: see text], and then divide each volume-limited main galaxy sample into two subsamples with low SFRs and high SFRs or low SSFRs and high SSFRs. A strong dependence of the clustering properties on SFR and SSFR is found: high SFR and SSFR galaxies are preferentially isolated or found in close pairs and small groups, whereas low SFR and SSFR galaxies preferentially inhabit dense groups and clusters.


2009 ◽  
Vol 5 (S267) ◽  
pp. 464-464
Author(s):  
J. A. Vázquez-Mata ◽  
H. M. Hernández-Toledo ◽  
Changbom Park ◽  
Yun-Young Choi

We present a new catalog of isolated galaxies (coined as UNAM–KIAS) obtained through an automated systematic search. The 1520 isolated galaxies were found in ~ 1.4 steradians of the sky in the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) photometry. The selection algorithm was implemented from a variation of the criteria developed by Karachentseva (1973), with full redshift information. This new catalog is aimed to carry out comparative studies of environmental effects and constraining the currently competing scenarios of galaxy formation and evolution.


Author(s):  
Xin-Fa Deng ◽  
Guisheng Yu ◽  
Peng Jiang

AbstractUsing two volume-limited Main galaxy samples of the Sloan Digital Sky Survey Data Release 7 , we explore influences of galaxy interactions on AGN activity. It is found that in the faint volume-limited sample, paired galaxies have a slightly higher AGN fraction than isolated galaxies, whereas in the luminous volume-limited sample, an opposite trend can be observed. The significance is <1σ. Thus, we do not observe strong evidence that interactions or mergers likely trigger the AGN activity.


2003 ◽  
Vol 599 (2) ◽  
pp. 971-991 ◽  
Author(s):  
A. M. Hopkins ◽  
C. J. Miller ◽  
R. C. Nichol ◽  
A. J. Connolly ◽  
M. Bernardi ◽  
...  

2020 ◽  
Vol 493 (2) ◽  
pp. 1686-1707 ◽  
Author(s):  
Yifei Luo ◽  
S M Faber ◽  
Aldo Rodríguez-Puebla ◽  
Joanna Woo ◽  
Yicheng Guo ◽  
...  

ABSTRACT This paper studies pseudo-bulges (P-bulges) and classical bulges (C-bulges) in Sloan Digital Sky Survey (SDSS) central galaxies using the new bulge indicator ΔΣ1, which measures relative central stellar-mass surface density within 1 kpc. We compare ΔΣ1 to the established bulge-type indicator Δ〈μe〉 from Gadotti (2009) and show that classifying by ΔΣ1 agrees well with Δ〈μe〉. ΔΣ1 requires no bulge–disc decomposition and can be measured on SDSS images out to z = 0.07. Bulge types using it are mapped on to 20 different structural and stellar-population properties for 12 000 SDSS central galaxies with masses 10.0 &lt; log M*/M⊙ &lt; 10.4. New trends emerge from this large sample. Structural parameters show fairly linear log–log relations versus ΔΣ1 and Δ〈μe〉 with only moderate scatter, while stellar-population parameters show a highly non-linear ‘elbow’ in which specific star formation rate remains roughly flat with increasing central density and then falls rapidly at the elbow, where galaxies begin to quench. P-bulges occupy the low-density end of the horizontal arm of the elbow and are universally star forming, while C-bulges occupy the elbow and the vertical branch and exhibit a wide range of star formation rates at a fixed density. The non-linear relation between central density and star formation rate has been seen before, but this mapping on to bulge class is new. The wide range of star formation rates in C-bulges helps to explain why bulge classifications using different parameters have sometimes disagreed in the past. The elbow-shaped relation between density and stellar indices suggests that central structure and stellar populations evolve at different rates as galaxies begin to quench.


2010 ◽  
Vol 6 (S277) ◽  
pp. 178-181
Author(s):  
Sara L. Ellison ◽  
David R. Patton ◽  
Preethi Nair ◽  
Luc Simard ◽  
J. Trevor Mendel ◽  
...  

AbstractGalaxy-galaxy interactions and large scale galaxy bars are usually considered as the two main mechanisms for driving gas to the centres of galaxies. By using large samples of galaxy pairs and visually classified bars from the Sloan Digital Sky Survey (SDSS), we compare the relative efficiency of gas inflows from these two processes. We use two indicators of gas inflow: star formation rate (SFR) and gas phase metallicity, which are both measured relative to control samples. Whereas the metallicity of galaxy pairs is suppressed relative to its control sample of isolated galaxies, galaxies with bars are metal-rich for their stellar mass by 0.06 dex over all stellar masses. The SFRs of both the close galaxy pairs and the barred galaxies are enhanced by ~60%, but in the bars the enhancement is only seen at stellar masses M∗ > 1010 M⊙. Taking into account the relative frequency of bars and pairs, we estimate that at least three times more central star formation is triggered by bars than by interactions.


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