2012ApJ...748..146C


C.D.S. - SIMBAD4 rel 1.7 - 2021.06.23CEST05:04:25

2012ApJ...748..146C - Astrophys. J., 748, 146 (2012/April-1)

A highly collimated water maser bipolar outflow in the Cepheus A HW3d massive young stellar object.

CHIBUEZE J.O., IMAI H., TAFOYA D., OMODAKA T., KAMEYA O., HIROTA T., CHONG S.-N. and TORRELLES J.M.

Abstract (from CDS):

We present the results of multi-epoch very long baseline interferometry (VLBI) water (H2O) maser observations carried out with the VLBI Exploration of Radio Astrometry toward the Cepheus A HW3d object. We measured for the first time relative proper motions of the H2 O maser features, whose spatio-kinematics traces a compact bipolar outflow. This outflow looks highly collimated and expanding through ∼280 AU (400 mas) at a mean velocity of ∼21 km/s (∼6 mas/yr) without taking into account the turbulent central maser cluster. The opening angle of the outflow is estimated to be ∼30°. The dynamical timescale of the outflow is estimated to be ∼100 years. Our results provide strong support that HW3d harbors an internal massive young star, and the observed outflow could be tracing a very early phase of star formation. We also have analyzed Very Large Array archive data of 1.3 cm continuum emission obtained in 1995 and 2006 toward Cepheus A. The comparative result of the HW3d continuum emission suggests the possibility of the existence of distinct young stellar objects in HW3d and/or strong variability in one of their radio continuum emission components.

Abstract Copyright:

Journal keyword(s): ISM: individual: Cepheus A - ISM: jets and outflows - masers - stars: formation

Simbad objects: 7

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Number of rows : 7

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 8C 2007+777 BLL 20 05 30.9981060951 +77 52 43.245329882     16.5 17.36   ~ 415 1
2 QSO J2015+371 BLL 20 15 28.7298087 +37 10 59.514637     21.82 21.4   ~ 255 2
3 NAME BL Lac BLL 22 02 43.2913773726 +42 16 39.978417860   15.66 14.72     ~ 2055 1
4 NAME Cep A HW 2 Y*O 22 56 17.9 +62 01 49           B0.5 204 0
5 NAME Cepheus A SFR 22 56 17.9 +62 01 49           ~ 709 2
6 [HW84] 3d Rad 22 56 18.2 +62 01 46           ~ 29 0
7 ICRF J230241.3+640552 Bz? 23 02 41.31499697 +64 05 52.8488544           ~ 33 1

    Equat.    Gal    SGal    Ecl

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2021.06.23-05:04:26

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