Stellar Populations of Galaxies in the LAMOST Spectral Survey

Abstract We first derive the stellar population properties: age and metallicity for ∼43,000 low redshift galaxies in the DR7 of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) survey, which have no spectroscopic observations in the Sloan Digital Sky Survey (SDSS). We employ a fitting procedure based on the small-scale features of galaxy spectra so as to avoid possible biases from the uncertain flux calibration of the LAMOST spectroscopy. We show that our algorithm can successfully recover the average age and metallicity of the stellar populations of galaxies down to signal-to-noise ratio ≥5 through testing on both mock galaxies and real galaxies comprising LAMOST and their SDSS counterparts. We provide a catalog of the age and metallicity for ∼43,000 LAMOST galaxies online. As a demonstration of the scientific application of this catalog, we present the Holmberg effect on both age and metallicity of a sample of galaxies in galaxy pairs.

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The weak imprint of environment on the stellar populations of galaxies

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3545 ◽

2020 ◽

Vol 500 (4) ◽

pp. 4469-4490 ◽

Cited By ~ 1

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 (<0.1 dex) and older (<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 (<0.03 dex) and age (<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 (<0.05 and <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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Clustering and Halo Occupation Distribution of Active Galactic Nuclei

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314003937 ◽

2013 ◽

Vol 9 (S304) ◽

pp. 243-243

Author(s):

Takamitsu Miyaji ◽

M. Krumpe ◽

A. Coil ◽

H. Aceves ◽

B. Husemann

Keyword(s):

Cross Correlation ◽

Dynamic Range ◽

Signal To Noise Ratio ◽

Sloan Digital Sky Survey ◽

Dark Matter Halo ◽

Bias Parameter ◽

X Ray ◽

Sky Survey ◽

Galaxy Population ◽

Halo Occupation Distribution

AbstractWe present the results of our series of studies on correlation function and halo occupation distribution of AGNs utilizing data the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) in the redshift range of 0.07<z<0.36. In order to improve the signal-to-noise ratio, we take cross-correlation approach, where cross-correlation functions (CCF) between AGNs and much more numerous AGNs are analyzed. The calculated CCFs are analyzed using the Halo Occupation Distribution (HOD) model, where the CCFs are divided into the term contributed by the AGN-galaxy pairs that reside in one dark matter halo (DMH), (the 1-halo term) and those from two different DMHs (the 2-halo term). The 2-halo term is the indicator of the bias parameter, which is a function of the typical mass of the DMHs in which AGNs reside. The combination of the 1-halo and 2-halo terms gives, not only the typical DMH mass, but also how the AGNs are distributed among the DMHs as a function of mass separately for those at the center of the DMHs and satellites. The main results are as follows: (1) the range of typical mass of the DMHs in various sub-samples of AGNs log (MDMH/h−1MΘ) ~ 12.4–13.4, (2) we found a dependence of the AGN bias parameter on the X-ray luminosity of AGNs, while the optical luminosity dependence is not significant probably due to smaller dynamic range in luminosity for the optically-selected sample, and (3) the growth of the number of AGNs per DMH (N (MDMH)) with MDMH is shallow, or even may be flat, contrary to that of the galaxy population in general, which grows with MDMH proportionally, suggesting a suppression of AGN triggering in denser environment. In order to investigate the origin of the X-ray luminosity dependence, we are also investigating the dependence of clustering on the black hole mass and the Eddington ratio, we also present the results of this investigation.

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The frequency of gaseous debris discs around white dwarfs

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa359 ◽

2020 ◽

Vol 493 (2) ◽

pp. 2127-2139 ◽

Cited By ~ 13

Author(s):

Christopher J Manser ◽

Boris T Gänsicke ◽

Nicola Pietro Gentile Fusillo ◽

Richard Ashley ◽

Elmé Breedt ◽

...

Keyword(s):

White Dwarf ◽

White Dwarfs ◽

Signal To Noise Ratio ◽

Infrared Emission ◽

Sloan Digital Sky Survey ◽

Emission Lines ◽

Occurrence Rate ◽

Limited Sample ◽

Sky Survey ◽

Gaseous Disc

ABSTRACT A total of 1–3 per cent of white dwarfs are orbited by planetary dusty debris detectable as infrared emission in excess above the white dwarf flux. In a rare subset of these systems, a gaseous disc component is also detected via emission lines of the Ca ii 8600 Å triplet, broadened by the Keplerian velocity of the disc. We present the first statistical study of the fraction of debris discs containing detectable amounts of gas in emission at white dwarfs within a magnitude and signal-to-noise ratio limited sample. We select 7705 single white dwarfs spectroscopically observed by the Sloan Digital Sky Survey (SDSS) and Gaia with magnitudes g ≤ 19. We identify five gaseous disc hosts, all of which have been previously discovered. We calculate the occurrence rate of a white dwarf hosting a debris disc detectable via Ca ii emission lines as $0.067\, \pm \, ^{0.042}_{0.025}$ per cent. This corresponds to an occurrence rate for a dusty debris disc to have an observable gaseous component in emission as 4 ± $_{2}^{4}$ per cent. Given that variability is a common feature of the emission profiles of gaseous debris discs, and the recent detection of a planetesimal orbiting within the disc of SDSS J122859.93+104032.9, we propose that gaseous components are tracers for the presence of planetesimals embedded in the discs and outline a qualitative model. We also present spectroscopy of the Ca ii triplet 8600 Å region for 20 white dwarfs hosting dusty debris discs in an attempt to identify gaseous emission. We do not detect any gaseous components in these 20 systems, consistent with the occurrence rate that we calculated.

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Stellar Populations in M31 from Broad-band Photometry

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311022770 ◽

2010 ◽

Vol 6 (S277) ◽

pp. 199-202

Author(s):

Antti Tamm ◽

Elmo Tempel ◽

Peeter Tenjes ◽

Taavi Tuvikene

Keyword(s):

Complex Structure ◽

Broad Band ◽

Far Infrared ◽

Stellar Populations ◽

Sloan Digital Sky Survey ◽

Spectral Energy ◽

3 Dimensional ◽

Sky Survey ◽

The Galaxy ◽

M 31

AbstractDue to its proximity, size, complex structure and high inclination angle, M31 offers an excellent opportunity for studying galactic structures outside the Milky Way and for drawing implications for their cosmological origin. We have studied the stellar populations of M 31 using the Sloan Digital Sky Survey (SDSS) photometry and the Spitzer far-infrared (FIR) mappings of dust. Combining these data, we have constructed a 3-dimensional model of the galaxy, laying constraints on the intrinsic (dust-free) properties of the galaxy and its stellar populations: their apparent and intrinsic luminosities, luminosity distributions, colours, shapes and sizes. We have interpreted the derived spectral energy distributions with synthetic stellar populations created with the Starburst99 software, in order to constrain the ages and masses of the stellar components.

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Extracting parameters for stellar populations of SDSS galaxy spectra using evolution strategies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307011970 ◽

2006 ◽

Vol 2 (14) ◽

pp. 599-599

Author(s):

Juan C. Gomez ◽

Olac Fuentes

Keyword(s):

Information Needs ◽

Stellar Populations ◽

Sloan Digital Sky Survey ◽

Evolution Strategies ◽

Huge Amount ◽

Useful Knowledge ◽

Amount Of Information ◽

Sky Survey

Current surveys from modern observatories contain a huge amount of information; in particular, the Sloan Digital Sky Survey (SDSS) has reached the order of terabytes of data in images and spectra. Such amount of information needs to be exploited by sophisticated algorithms that automatically analyze the data in order to extract useful knowledge from the mega databases.

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Galactic Stellar Populations in the Era of the Sloan Digital Sky Survey and Other Large Surveys

Annual Review of Astronomy and Astrophysics ◽

10.1146/annurev-astro-081811-125504 ◽

2012 ◽

Vol 50 (1) ◽

pp. 251-304 ◽

Cited By ~ 92

Author(s):

Željko Ivezić ◽

Timothy C. Beers ◽

Mario Jurić

Keyword(s):

Stellar Populations ◽

Sloan Digital Sky Survey ◽

Sky Survey ◽

Galactic Stellar Populations

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Dissecting galaxy triplets in the Sloan Digital Sky Survey Data Release 10 – I. Stellar populations and emission line analysis

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stw816 ◽

2016 ◽

Vol 459 (3) ◽

pp. 2539-2549

Author(s):

M. V. Costa-Duarte ◽

A. L. O'Mill ◽

F. Duplancic ◽

L. Sodré ◽

D. G. Lambas

Keyword(s):

Emission Line ◽

Survey Data ◽

Stellar Populations ◽

Sloan Digital Sky Survey ◽

Sky Survey ◽

Data Release ◽

Line Analysis

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Stellar populations in star forming galaxies in the Sloan Digital Sky Survey

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310003649 ◽

2009 ◽

Vol 5 (S262) ◽

pp. 446-447

Author(s):

Pieter Westera ◽

François Cuisinier ◽

Carlos R. Rabaça

Keyword(s):

Population Analysis ◽

Stellar Populations ◽

Stellar Mass ◽

Sloan Digital Sky Survey ◽

High Mass ◽

Synthesis Methods ◽

Young Generation ◽

Homogeneous Sample ◽

Star Forming ◽

Sky Survey

AbstractWe examine the star forming phenomenon as it can be encountered in galaxies in the Sloan Digital Sky Survey, which possibly contains the largest homogeneous sample of star forming galaxy spectra to date.After eliminating all spectra with an insufficient signal-to-noise ratio, without strong emission lines, and without the [OII] λ3727 Å line, which is necessary for the determination of the gas metallicity (which excludes galaxies with redshift ≲ 0.024–0.025), our sample contains ~6000 spectra of star forming galaxies.Through a detailed stellar population analysis employing evolutionary synthesis methods we determined the stellar composition of these galaxies, that is, the masses, ages and metallicities of their partial stellar populations.We find that most, possibly all, galaxies of our sample contain, apart from the presently bursting, ionising young generation (≤ 107 yrs), old (≥ 109 yrs) and intermediate (between 107 and 109 yrs) populations, whereas the old population dominates the stellar mass (but not the light).We also find that high (stellar) mass galaxies have higher gas metallicities and lower present star formation rates relative to their total (stellar) masses, than low mass galaxies, indicating a higher chemical evolution degree for high mass galaxies.Furthermore, we find that gas enrichment mechanisms in star forming galaxies do not vary with galactic mass, being the same for low- and high-mass galaxies on average. Gas enrichment mechanisms seem to present a greater variety at the high-mass end, though, indicating a more complex assembly history for high-mass galaxies.

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