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Title: Testing the Presence of Multiple Photometric Components in Nearby Early-type Galaxies Using SDSS

Abstract

We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are ∼3 and ∼15 kpc. The inner component lies on the mass–size relation of ETGs at z ∼ 0.25–0.75, while the outer component tends to be more elliptical and hints at a stochastic buildup process. We find real physical differences between single- and double-component ETGs, with double-component galaxies being younger and more metal-rich. The fraction of double-component ETGs increases with increasing σ and decreases in denser environments. We hypothesize that double-component systems were able to accrete gas and small galaxies until later times, boosting their central densities, building up their outer parts, and lowering their typical central ages. In contrast, the oldest galaxies, perhaps due to residing in richer environments, have no remaining hints of their last accretion episode.

Authors:
;  [1];  [2]
  1. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
  2. Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, the University of Tokyo, Kashiwa (Japan)
Publication Date:
OSTI Identifier:
22663815
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 836; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DECOMPOSITION; DENSITY; EVOLUTION; GALAXIES; IMAGES; MASS; METALS; PETROLEUM RESIDUES; STOCHASTIC PROCESSES; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Oh, Semyeong, Greene, Jenny E., and Lackner, Claire N., E-mail: semyeong@astro.princeton.edu. Testing the Presence of Multiple Photometric Components in Nearby Early-type Galaxies Using SDSS. United States: N. p., 2017. Web. doi:10.3847/1538-4357/836/1/115.
Oh, Semyeong, Greene, Jenny E., & Lackner, Claire N., E-mail: semyeong@astro.princeton.edu. Testing the Presence of Multiple Photometric Components in Nearby Early-type Galaxies Using SDSS. United States. doi:10.3847/1538-4357/836/1/115.
Oh, Semyeong, Greene, Jenny E., and Lackner, Claire N., E-mail: semyeong@astro.princeton.edu. Fri . "Testing the Presence of Multiple Photometric Components in Nearby Early-type Galaxies Using SDSS". United States. doi:10.3847/1538-4357/836/1/115.
@article{osti_22663815,
title = {Testing the Presence of Multiple Photometric Components in Nearby Early-type Galaxies Using SDSS},
author = {Oh, Semyeong and Greene, Jenny E. and Lackner, Claire N., E-mail: semyeong@astro.princeton.edu},
abstractNote = {We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are ∼3 and ∼15 kpc. The inner component lies on the mass–size relation of ETGs at z ∼ 0.25–0.75, while the outer component tends to be more elliptical and hints at a stochastic buildup process. We find real physical differences between single- and double-component ETGs, with double-component galaxies being younger and more metal-rich. The fraction of double-component ETGs increases with increasing σ and decreases in denser environments. We hypothesize that double-component systems were able to accrete gas and small galaxies until later times, boosting their central densities, building up their outer parts, and lowering their typical central ages. In contrast, the oldest galaxies, perhaps due to residing in richer environments, have no remaining hints of their last accretion episode.},
doi = {10.3847/1538-4357/836/1/115},
journal = {Astrophysical Journal},
number = 1,
volume = 836,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2017},
month = {Fri Feb 10 00:00:00 EST 2017}
}
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