TY - JOUR
T1 - A Novel Survey for Young Substellar Objects with the W-band Filter. II. The Coolest and Lowest Mass Members of the Serpens-South Star-forming Region
AU - Jose, Jessy
AU - Biller, Beth A.
AU - Albert, Loïc
AU - Dubber, Sophie
AU - Allers, Katelyn
AU - Herczeg, Gregory J.
AU - Liu, Michael C.
AU - Pearson, Samuel
AU - Lalchand, Bhavana
AU - Chen, Wen Ping
AU - Bonnefoy, Mickaël
AU - Artigau, Etienne
AU - Delorme, Philippe
AU - Chiang, Po Shih
AU - Zhang, Zhoujian
AU - Oasa, Yumiko
N1 - J.J. acknowledges the grant No. 11473005 awarded by the National Science Foundation of China to G.J.H.
PY - 2020/4/3
Y1 - 2020/4/3
N2 - Given its relative proximity (∼430 pc), compact size (<20′), young age (∼0.5 Myr), and rich number of young stellar objects, the Serpens-South star-forming region is a promising site for studying young substellar objects, yet the low-mass members of this region remain largely undiscovered. In this article we report on a deep photometric survey using a custom 1.45 μm filter (W band), as well as standard J and H near-IR filters, in order to identify candidate low-mass young brown dwarfs in the Serpens-South region. We constructed a reddening-insensitive index (Q) by combining J, H and W-band photometry for survey objects, in order to identify candidate low-mass members of Serpens based on the strength of the water-absorption feature at 1.45 μm in the atmospheres of mid-M and later objects. We then conducted spectroscopic follow-up to confirm youth and spectral type for our candidates. This is the first survey to identify the very low-mass and coolest members of Serpens-South. We identify four low-mass candidate Serpens members, which all display IR excess emission, indicating the likely presence of circumstellar disks around them. One of the four candidate low-mass members in our list, SERP182918-020245, exhibits Paβ and Brγ emission features, confirming its youth and ongoing magnetospheric accretion. Our new candidate members have spectral types >M4 and are the coolest and lowest mass candidate members yet identified in Serpens-South.
AB - Given its relative proximity (∼430 pc), compact size (<20′), young age (∼0.5 Myr), and rich number of young stellar objects, the Serpens-South star-forming region is a promising site for studying young substellar objects, yet the low-mass members of this region remain largely undiscovered. In this article we report on a deep photometric survey using a custom 1.45 μm filter (W band), as well as standard J and H near-IR filters, in order to identify candidate low-mass young brown dwarfs in the Serpens-South region. We constructed a reddening-insensitive index (Q) by combining J, H and W-band photometry for survey objects, in order to identify candidate low-mass members of Serpens based on the strength of the water-absorption feature at 1.45 μm in the atmospheres of mid-M and later objects. We then conducted spectroscopic follow-up to confirm youth and spectral type for our candidates. This is the first survey to identify the very low-mass and coolest members of Serpens-South. We identify four low-mass candidate Serpens members, which all display IR excess emission, indicating the likely presence of circumstellar disks around them. One of the four candidate low-mass members in our list, SERP182918-020245, exhibits Paβ and Brγ emission features, confirming its youth and ongoing magnetospheric accretion. Our new candidate members have spectral types >M4 and are the coolest and lowest mass candidate members yet identified in Serpens-South.
U2 - 10.3847/1538-4357/ab74dd
DO - 10.3847/1538-4357/ab74dd
M3 - Article
AN - SCOPUS:85085116787
SN - 0004-637X
VL - 892
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 122
ER -