2013A&A...556A.129T


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.20CET07:10:42

2013A&A...556A.129T - Astronomy and Astrophysics, volume 556A, 129-129 (2013/8-1)

LkHα 101 at millimeter wavelengths.

THUM C., NERI R., BAEZ-RUBIO A. and KRIPS M.

Abstract (from CDS):

We present new millimeter observations made with the IRAM interferometer and 30m telescope of the ionized wind from the massive young stellar object LkHα101. Several recombination lines, including higher order transitions, were detected for the first time at radio wavelengths in this source. From three α-transitions, we derive an accurate value for the stellar velocity and for the first time, an unambiguous expansion velocity of the wind that is 55km/s. This velocity is much slower than reported previously, and the resulting mass loss rate is 1.8x10–6M/yr. The wideband continuum spectra and the interferometer visibilities show that the density of the wind falls off more steeply than what is compatible with constant-velocity expansion. We argue that these properties indicate that the wind is launched from a radially narrow region of the circumstellar disk, and we propose that slow speed and a steep density gradient are characteristic properties of the evolutionary phase, where young stars of intermediate and high mass clear away the gaseous component of their accretion disks. The recombination lines are emitted close to local thermal equilibrium, but the higher order transitions appear systematically broader and weaker than expected, probably because of impact broadening. Finally, we show that LkHα101 shares many properties with MWC349, the only other stellar wind source where radio recombination lines have been detected, with some of them masing. We argue that LkHα101 evades masing at millimeter wavelengths because of the disk's smaller size and unfavorable orientation. Some amplification may however be detectable at shorter wavelengths.

Abstract Copyright:

Journal keyword(s): radio lines: stars - stars: winds, outflows - radio continuum: stars - X-rays: diffuse background

Simbad objects: 9

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Number of rows : 9

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 BD+57 607a Be* 02 40 09.2293277647 +57 45 41.680428747   11.35 10.73     Be 11 0
2 ICRF J041437.2+341851 Bz? 04 14 37.25574837 +34 18 51.2071581       22.83   ~ 25 1
3 3C 111 Sy1 04 18 21.2773655604 +38 01 35.801523843   19.75 18.05     ~ 841 1
4 LDN 1482 DNe 04 28.3 +35 37           ~ 17 0
5 NGC 1579 HII 04 30 11 +35 16.7           ~ 70 1
6 EM* LkHA 101 Em* 04 30 14.438 +35 16 24.03   17.91 15.71 13.33   F 291 1
7 NAME Taurus Dark Cloud SFR 04 41.0 +25 52           ~ 3323 0
8 3C 273 BLL 12 29 06.6996828061 +02 03 08.598846466   13.05 14.830 14.11   ~ 5245 1
9 EM* MWC 349 Em* 20 32 45.6328 +40 39 36.143   15.88 13.15 12.13   Bep 691 1

    Equat.    Gal    SGal    Ecl

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2019.11.20-07:10:42

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