TY - JOUR
T1 - Disk Structure around the Class i Protostar L1489 IRS Revealed by ALMA
T2 - A Warped-disk System
AU - Sai, Jinshi
AU - Ohashi, Nagayoshi
AU - Saigo, Kazuya
AU - Matsumoto, Tomoaki
AU - Aso, Yusuke
AU - Takakuwa, Shigehisa
AU - Aikawa, Yuri
AU - Kurose, Ippei
AU - Yen, Hsi Wei
AU - Tomisaka, Kohji
AU - Tomida, Kengo
AU - MacHida, Masahiro N.
N1 - Funding Information:
2020-04-01 2020-04-15 14:10:52 cgi/release: Article released bin/incoming: New from .zip JSPS KAKENHI JP18K03703 NAOJ ALMA scientific Research 2019-13B MOST 108-2112-M-001-003-MY2 JSPS KAKENHI JP18H05436 JSPS KAKENHI JP18H05437 JSPS KAKENHI JP17K05394 JSPS KAKENHI JP17H02863 yes
PY - 2020/4/10
Y1 - 2020/4/10
N2 - We have observed the Class I protostar L1489 IRS with the Atacama Millimeter/submillimeter Array (ALMA) in Band 6. The C18O J = 2-1 line emission shows flattened and non-axisymmetric structures in the same direction as its velocity gradient due to rotation. We discovered that the C18O emission shows dips at a radius of ∼200-300 au while the 1.3 mm continuum emission extends smoothly up to r ∼ 400 au. At the radius of the C18O dips, the rotational axis of the outer portion appears to be tilted by ∼15° from that of the inner component. Both the inner and outer components with respect to the C18O dips exhibit the r -0.5 Keplerian rotation profiles until r ∼ 600 au. These results not only indicate that a Keplerian disk extends up to ∼600 au but also that the disk is warped. We constructed a three-dimensional warped-disk model rotating at the Keplerian velocity, and demonstrated that the warped-disk model reproduces main observed features in the velocity channel maps and the PV diagrams. Such a warped-disk system can form by mass accretion from a misaligned envelope. We also discuss a possible disk evolution scenario based on comparisons of disk radii and masses between Class I and Class II sources.
AB - We have observed the Class I protostar L1489 IRS with the Atacama Millimeter/submillimeter Array (ALMA) in Band 6. The C18O J = 2-1 line emission shows flattened and non-axisymmetric structures in the same direction as its velocity gradient due to rotation. We discovered that the C18O emission shows dips at a radius of ∼200-300 au while the 1.3 mm continuum emission extends smoothly up to r ∼ 400 au. At the radius of the C18O dips, the rotational axis of the outer portion appears to be tilted by ∼15° from that of the inner component. Both the inner and outer components with respect to the C18O dips exhibit the r -0.5 Keplerian rotation profiles until r ∼ 600 au. These results not only indicate that a Keplerian disk extends up to ∼600 au but also that the disk is warped. We constructed a three-dimensional warped-disk model rotating at the Keplerian velocity, and demonstrated that the warped-disk model reproduces main observed features in the velocity channel maps and the PV diagrams. Such a warped-disk system can form by mass accretion from a misaligned envelope. We also discuss a possible disk evolution scenario based on comparisons of disk radii and masses between Class I and Class II sources.
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U2 - 10.3847/1538-4357/ab8065
DO - 10.3847/1538-4357/ab8065
M3 - Article
AN - SCOPUS:85084751115
VL - 893
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 51
ER -