UV Spectral Slope and Nebular Dust Attenuation in Dwarf Galaxies at $1.4<z<2.6$

Fuente: arXiv
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Autori principali: Alavi, Anahita, Siana, Brian, Teplitz, Harry I., Gburek, Timothy, Colbert, James, Mehta, Vihang, Emami, Najmeh, Freeman, William R., Richard, Johan, Kim, Keunho
Natura: Preprint
Pubblicazione: 2025
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author Alavi, Anahita
Siana, Brian
Teplitz, Harry I.
Gburek, Timothy
Colbert, James
Mehta, Vihang
Emami, Najmeh
Freeman, William R.
Richard, Johan
Kim, Keunho
author_facet Alavi, Anahita
Siana, Brian
Teplitz, Harry I.
Gburek, Timothy
Colbert, James
Mehta, Vihang
Emami, Najmeh
Freeman, William R.
Richard, Johan
Kim, Keunho
contents We analyze nebular dust attenuation and its correlation with stellar mass ($M_{*}$) and UV spectral slope ($β$) in 33 lensed, low-mass star-forming galaxies at $1.4\leq z \leq 2.6$, using Keck/MOSFIRE rest-frame optical spectroscopy. Located behind three massive lensing galaxy clusters Abell 1689, MACS J1149.5+2223, and MACS J0717.5+3745, galaxies in our sample have a median stellar mass of $\log(M_{*}/M_{\odot})=8.3$ and an intrinsic UV absolute magnitude range of $-20.9<M_{UV}<-13$. We measure nebular dust attenuation via Balmer optical depth ($τ_{B}$) defined as the H$α$/H$β$ ratio. We also derive physical properties from Hubble Space Telescope multi-wavelength photometry and construct composite spectra using median stacking in bins of $M_{*}$ and $β$. We find that the $τ_{B}-β$ relation for the dwarf galaxies in this study is best represented by SMC dust curve. This is consistent with previous studies of low-metallicity galaxies at similar redshifts, which show a steep attenuation curve similar to the SMC curve, in contrast to high-metallicity and more massive galaxies that exhibit a much shallower dust attenuation curve. We also investigate the relationship between nebular dust attenuation and stellar mass, $E(B-V)_{nebular}-M_{*}$, down to $\log(M_{*}/M_{\odot})\sim 7$. We demonstrate that this relation does not notably evolve with redshift and is consistent with what has been observed for local SDSS galaxies at similar low stellar masses.
format Preprint
id arxiv_https___arxiv_org_abs_2510_00427
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle UV Spectral Slope and Nebular Dust Attenuation in Dwarf Galaxies at $1.4<z<2.6$
Alavi, Anahita
Siana, Brian
Teplitz, Harry I.
Gburek, Timothy
Colbert, James
Mehta, Vihang
Emami, Najmeh
Freeman, William R.
Richard, Johan
Kim, Keunho
Astrophysics of Galaxies
We analyze nebular dust attenuation and its correlation with stellar mass ($M_{*}$) and UV spectral slope ($β$) in 33 lensed, low-mass star-forming galaxies at $1.4\leq z \leq 2.6$, using Keck/MOSFIRE rest-frame optical spectroscopy. Located behind three massive lensing galaxy clusters Abell 1689, MACS J1149.5+2223, and MACS J0717.5+3745, galaxies in our sample have a median stellar mass of $\log(M_{*}/M_{\odot})=8.3$ and an intrinsic UV absolute magnitude range of $-20.9<M_{UV}<-13$. We measure nebular dust attenuation via Balmer optical depth ($τ_{B}$) defined as the H$α$/H$β$ ratio. We also derive physical properties from Hubble Space Telescope multi-wavelength photometry and construct composite spectra using median stacking in bins of $M_{*}$ and $β$. We find that the $τ_{B}-β$ relation for the dwarf galaxies in this study is best represented by SMC dust curve. This is consistent with previous studies of low-metallicity galaxies at similar redshifts, which show a steep attenuation curve similar to the SMC curve, in contrast to high-metallicity and more massive galaxies that exhibit a much shallower dust attenuation curve. We also investigate the relationship between nebular dust attenuation and stellar mass, $E(B-V)_{nebular}-M_{*}$, down to $\log(M_{*}/M_{\odot})\sim 7$. We demonstrate that this relation does not notably evolve with redshift and is consistent with what has been observed for local SDSS galaxies at similar low stellar masses.
title UV Spectral Slope and Nebular Dust Attenuation in Dwarf Galaxies at $1.4<z<2.6$
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2510.00427