A simple numerical experiment on the dust temperature bias for Lyman break galaxies at $z\gtrsim 5$

Yung Ying Chen; Hiroyuki Hirashita; Wei-Hao Wang; Naomasa Nakai

doi:10.1093/mnras/stab3142

paper

A simple numerical experiment on the dust temperature bias for Lyman break galaxies at $z ≳ 5$

arXiv:2110.14135 · doi:10.1093/mnras/stab3142

Abstract

Some studies suggest that the dust temperatures ( $T_{d}$ ) in high-redshift ( $z ≳ 5$ ) Lyman break galaxies (LBGs) are high. However, possible observational bias in $T_{d}$ is yet to be understood. Thus, we perform a simple test using random realizations of LBGs with various stellar masses, dust temperatures, and dust-to-stellar mass ratios, and examine how the sample detected by ALMA is biased in terms of $T_{d}$ . We show that ALMA tends to miss high- $T_{d}$ objects even at total dust luminosity. LBGs are, however, basically selected by the stellar UV luminosity. The dust-temperature bias in a UV-selected sample is complicated because of the competing effects between high $T_{d}$ and low dust abundance. For ALMA Band 6, there is no tendency of high- $T_{d}$ LBGs being more easily detected in our experiment. Thus, we suggest that the observed trend of high $T_{d}$ in $z ≳ 5$ LBGs is real. We also propose that the 450 $μ$ m band is useful in further clarifying the dust temperatures. To overcome the current shallowness of 450 $μ$ m observations, we examine a future Antarctic 30-m class telescope with a suitable atmospheric condition for wavelengths $≲ 450 μ$ m, where the detection is not confusion-limited. We find that, with this telescope, an $L_{IR}$ -selected sample with $lo g (L_{IR} / L_{⊙}) > 11$ is constructed for $z ≳ 5$ , and detection in the intermediate- $M_{⋆}$ (stellar mass) range [ $9 < lo g (M_{⋆} / M_{⊙}) < 9.5$ ] is much improved, especially at high $T_{d}$ .

arXiv comment11 pages, 6 figures, accepted for publication in MNRAS

A simple numerical experiment on the dust temperature bias for Lyman break galaxies at $z ≳ 5$

Abstract

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A simple numerical experiment on the dust temperature bias for Lyman break galaxies at z≳5

Abstract

References in corpus (67)

Cited by in corpus (3)

A simple numerical experiment on the dust temperature bias for Lyman break galaxies at $z ≳ 5$