2024-03-29T14:39:50Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:02001526
2023-01-16T05:16:07Z
2026:2027:2028
The 2175 Å Dust Feature in Star-forming Galaxies at 1.3 ≤ z ≤ 1.8: The Dependence on Stellar Mass and Specific Star Formation Rate
Kashino, Daichi
Lilly, Simon J.
Silverman, John D.
Renzini, Alvio
Daddi, Emanuele
Bardelli, Sandro
Cucciati, Olga
Kartaltepe, Jeyhan S.
Mainieri, Vincenzo
Pelló, Roser
Peng, Ying-jie
Sanders, David B.
Zucca, Elena
open access
© 2021. The American Astronomical Society
We present direct spectroscopic measurements of the broad 2175 Å absorption feature in 505 star-forming main-sequence galaxies at 1.3 ≤ z ≤ 1.8 using individual and stacked spectra from the zCOSMOS-deep survey. Significant 2175 Å excess absorption features of moderate strength are measured, especially in the composite spectra. The excess absorption is well described by a Drude profile. The bump amplitude expressed in units of k(λ) = A(λ)/E(B − V), relative to the featureless Calzetti et al. law, has a range Bk ≈ 0.2–0.8. The bump amplitude decreases with the specific star formation rate (sSFR), while it increases moderately with the stellar mass. However, a comparison with local "starburst" galaxies shows that the high-redshift main-sequence galaxies have stronger bump features, despite having a higher sSFR than the local sample. Plotting the bump strength against the △logsSFR≡log(SFR/SFR MS) relative to the main sequence, however, brings the two samples into much better concordance. This may indicate that it is the recent star formation history of the galaxies that determines the bump strength through the destruction of small carbonaceous grains by supernovae and intense radiation fields coupled with the time delay of ∼1 Gyr in the appearance of carbon-rich asymptotic giant branch stars.
IOP publishing
2021-10-15
2021-03-19
eng
journal article
VoR
http://hdl.handle.net/2237/0002001526
https://nagoya.repo.nii.ac.jp/records/2001526
https://doi.org/10.3847/1538-4357/abdf62
0004-637X
The Astrophysical Journal
909
2
213
https://nagoya.repo.nii.ac.jp/record/2001526/files/Kashino_2021_ApJ_909_213.pdf
application/pdf
2.6 MB
2021-10-15