TY - JOUR
T1 - The MOSDEF survey
T2 - probing resolved stellar populations at z ∼ 2 Using a new bayesian-defined morphology metric called patchiness
AU - Fetherolf, Tara
AU - Reddy, Naveen A.
AU - Shapley, Alice E.
AU - Kriek, Mariska
AU - Siana, Brian
AU - Coil, Alison L.
AU - Mobasher, Bahram
AU - Freeman, William R.
AU - Price, Sedona H.
AU - Sanders, Ryan L.
AU - Shivaei, Irene
AU - Azadi, Mojegan
AU - de Groot, Laura
AU - Leung, Gene C.K.
AU - Zick, Tom O.
N1 - Publisher Copyright:
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2023/1/1
Y1 - 2023/1/1
N2 - We define a new morphology metric called ‘patchiness’ (P) that is sensitive to deviations from the average of a resolved distribution, does not require the galaxy centre to be defined, and can be used on the spatially resolved distribution of any galaxy property. While the patchiness metric has a broad range of applications, we demonstrate its utility by investigating the distribution of dust in the interstellar medium (ISM) of 310 star-forming galaxies at spectroscopic redshifts 1.36 < z < 2.66 observed by the MOSFIRE Deep Evolution Field survey. The stellar continuum reddening distribution, derived from high-resolution multiwaveband CANDELS/3D-HST imaging, is quantified using the patchiness, Gini, and M20 coefficients. We find that the reddening maps of high-mass galaxies, which are dustier and more metal-rich on average, tend to exhibit patchier distributions (high P) with the reddest components concentrated within a single region (low M20). Our results support a picture where dust is uniformly distributed in low-mass galaxies (≲1010 M☉), implying efficient mixing of dust throughout the ISM. On the other hand, the dust distribution is patchier in high-mass galaxies (≳1010 M☉). Dust is concentrated near regions of active star formation and dust mixing time-scales are expected to be longer in high-mass galaxies, such that the outskirt regions of these physically larger galaxies remain relatively unenriched. This study presents direct evidence for patchy dust distributions on scales of a few kpc in high-redshift galaxies, which previously has only been suggested as a possible explanation for the observed differences between nebular and stellar continuum reddening, star formation rate indicators, and dust attenuation curves.
AB - We define a new morphology metric called ‘patchiness’ (P) that is sensitive to deviations from the average of a resolved distribution, does not require the galaxy centre to be defined, and can be used on the spatially resolved distribution of any galaxy property. While the patchiness metric has a broad range of applications, we demonstrate its utility by investigating the distribution of dust in the interstellar medium (ISM) of 310 star-forming galaxies at spectroscopic redshifts 1.36 < z < 2.66 observed by the MOSFIRE Deep Evolution Field survey. The stellar continuum reddening distribution, derived from high-resolution multiwaveband CANDELS/3D-HST imaging, is quantified using the patchiness, Gini, and M20 coefficients. We find that the reddening maps of high-mass galaxies, which are dustier and more metal-rich on average, tend to exhibit patchier distributions (high P) with the reddest components concentrated within a single region (low M20). Our results support a picture where dust is uniformly distributed in low-mass galaxies (≲1010 M☉), implying efficient mixing of dust throughout the ISM. On the other hand, the dust distribution is patchier in high-mass galaxies (≳1010 M☉). Dust is concentrated near regions of active star formation and dust mixing time-scales are expected to be longer in high-mass galaxies, such that the outskirt regions of these physically larger galaxies remain relatively unenriched. This study presents direct evidence for patchy dust distributions on scales of a few kpc in high-redshift galaxies, which previously has only been suggested as a possible explanation for the observed differences between nebular and stellar continuum reddening, star formation rate indicators, and dust attenuation curves.
KW - dust, extinction
KW - galaxies: ISM
KW - galaxies: evolution
KW - galaxies: high-redshift
KW - galaxies: structure
KW - methods: data analysis
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UR - http://www.scopus.com/inward/citedby.url?scp=85159120877&partnerID=8YFLogxK
U2 - 10.1093/mnras/stac3362
DO - 10.1093/mnras/stac3362
M3 - Article
AN - SCOPUS:85159120877
SN - 0035-8711
VL - 518
SP - 4214
EP - 4237
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -