A Complete 16 $\mu$m selected Galaxy Sample at $z \sim 1$. II: Morphological Analysis
We present morphological analysis of the 16$\mu$m flux-density-limited galaxy sample at 0.8$<z<$1.3 from arXiv:2103.04585. At the targeted redshift, the 16$\mu$m emission corresponds to the Polycyclic aromatic hydrocarbon (PAH) feature from intense star formation, or dust heated by AGN (Active...
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Main Authors | , , , , |
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Format | Journal Article |
Language | English |
Published |
11.05.2024
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Subjects | |
Online Access | Get full text |
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Summary: | We present morphological analysis of the 16$\mu$m flux-density-limited galaxy
sample at 0.8$<z<$1.3 from arXiv:2103.04585. At the targeted redshift, the
16$\mu$m emission corresponds to the Polycyclic aromatic hydrocarbon (PAH)
feature from intense star formation, or dust heated by AGN (Active galactic
nuclei). Our sample of 479 galaxies are dominated by Luminous Infrared Galaxies
(LIRGs, 67\%) in three CANDLES fields (EGS, GOODS-N, and GOODS-S), and are
further divided into AGN dominated, star-forming dominated, composite, and blue
compact galaxies by their spectral energy distribution (SED) types. The
majority of our sample (71\%) have disky morphologies, with the few AGN
dominated galaxies being more bulge-dominanted than the star-forming dominated
and composite galaxies. The distribution of our sample on the Gini vs.
M$_{\text{20}}$ plane is consistent with previous studies, where the S\'ersic
index $n$ shows an increasing trend towards the smaller M$_{\text{20}}$ and
higher Gini region below the dividing line for mergers. The subsample of ULIRGs
follow a steep size-mass relation that is closer to the early-type galaxies. In
addition, as the 4.5 $\mu$m luminosity excess ($L_{4.5}^{Exc}$, proxy for AGN
strength) increases, our sample appear to be more bulge-dominated (i.e. higher
$n$). Based on the sSFR and compactness ($log_{10}\Sigma_{1.5},
\Sigma_{1.5}=M_*/R_e^{1.5}$) diagram, the majority of our LIRG-dominated galaxy
sample follow a secular evolution track, and their distribution can be
explained without involving any merging activities. Out of the 16 ULIRGs in our
sample, six are compact with strong AGN contributions, likely evolving along
the fast-track from more violent activities. |
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DOI: | 10.48550/arxiv.2405.06984 |