Studying [C II] emission in low-mass galaxies at z ~ 7

Glazer, Kelsey (author), Bradač, Maruša (author), Sanders, Ryan L. (author), Fujimoto, Seiji (author), Bolan, Patricia (author), Ferrara, Andrea (author), Strait, Victoria (author), Jones, Tucker (author), Lemaux, Brian C. (author)

We report on a [CII]$_{158\mu\mathrm{m}}$ search using the Atacama Large Millimeter/submillimeter Array (ALMA) on three lensed, confirmed Ly$\alpha$ emitting galaxies at z ∼ 7. Our targets are ultraviolet (UV) faint systems with stellar masses on the order of M$_*$ ∼ $10^9\ \mathrm{M}_{\odot}$. We detect a single [C II] line emission (4$\sigma$) from the brightest (L ∼ 2.4 × $10^{10}\ \mathrm{L}_\odot$) galaxy in our sample, MACS0454-1251. We determine a systemic redshift (z$_{[C II]}$ = 6.3151 ± 0.0005) for MACS0454-1251 and measure a Ly$\alpha$ velocity offset of $\Delta v \approx 300 \pm 70\mathrm{km\ s^{-1}}$⁠. The remaining two galaxies we detect no [C II] but provide 3$\sigma$ upper limits on their [C II] line luminosities which we use to investigate the $L_{[C II]}-\mathrm{SFR}$ relation. Overall our single [C II] detection shows agreement with the relation for local dwarf galaxies. Our [C II] deficient galaxies could potentially be exhibiting low metallicities (Z < Z$_{\odot}$). Another possible explanation for weaker [C II] emission could be strong feedback from star formation disrupting molecular clouds. We do not detect continuum emission in any of the sources, placing upper limits on their dust masses. Assuming a single dust temperature of $T_d=35\mathrm{K}$ dust masses ($\mathrm{M_{dust}}$) range from < 4.8 × $10^7\ \mathrm{M}_\odot$ to 2.3 × $10^8\ \mathrm{M}_\odot$. Collectively, our results suggest faint reionization era sources could be metal poor and/or could have strong feedback suppressing [C II] emission.

• Language: English
• Keywords: high-redshift galaxies, gravitational lensing
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 945-952
• Numbering: Vol. 531, iss. 1
• PID: 20.500.12556/RUL-160387
• UDC: 524.8
• ISSN on article: 1365-2966
• DOI: 10.1093/mnras/stae1178
• COBISS.SI-ID: 205494275
• Publication date in RUL: 27.08.2024

Record is a part of a journal

• Title: Monthly notices of the Royal Astronomical Society
• Shortened title: Mon. not. R. Astron. Soc.
• Publisher: Blackwell Science
• ISSN: 1365-2966
• COBISS.SI-ID: 1870180

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: galaksije z velikim rdečim premikom, gravitacijsko lečenje