J/A+A/281/161 Radio emission from stars at 250GHz (Altenhoff+, 1994)
Radio emission from stars: a survey at 250 GHz
Altenhoff W.J., Thum C., Wendker H.J.
<Astron. Astrophys. 281, 161 (1994)>
=1994A&A...281..161A 1994A&A...281..161A
ADC_Keywords: Stars, radio; Stars, OB; Stars, Wolf-Rayet; Stars, early-type;
Stars, pre-main sequence; Stars, giant; Stars, supergiant;
Stars, variable
Keywords: radio stars - stellar wind - Wolf-Rayet stars -
giants and supergiants - pre-main sequence stars - variable stars
Abstract:
We have used the IRAM 30 m-telescope together with the Max Planck
Institute for Radio Astronomy (MPIfR) bolometer to survey nearly 270
stars of different types for 250GHz continuum emission. We compare
these data with their low frequency (cm-range) properties. Early type
stars show very often a deviation from the uniformly expanding wind
model which we tentatively attribute to temperature and/or density
fluctuations in their deeper atmospheric layers. For WR stars this
deviation seems to depend on the effective temperature. Pre-main
sequence stars usually seem to be surrounded by a shell of warm dust
making a substantial contribution to the 250 GHz flux density value.
We have found especially for nearby giants and supergiants that a
layer at the transition from photosphere to chromosphere emits ample
250 GHz radiation. We show that the present data can still be
explained by a simple uniformly illuminated disk model with the known
stellar radius. Optically variable stars are not very strong emitters
at 250 GHz. We preferentially detected the more exotic ones, a few
Beta Lyr-type and symbiotic stars. Comments on many individual objects
are given in the appropriate sections.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 98 21 O and B stars
table5.dat 95 24 WR stars
table6.dat 98 10 Early-type stars with shelles
table7.dat 90 42 Pre-main sequence stars
table8.dat 90 95 Stellar disks (giants+supergiants)
table9.dat 53 28 Stars with determined radii
table10.dat 90 76 Variable stars
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Byte-per-byte Description of file: table[4-8].dat table10.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Star name
17- 27 A11 --- SpType MK spectral type (table8 only)
29 A1 --- l_S(250) Limit flag on S(250)
30- 35 F6.1 mJy S(250) ? Flux in continuum at 250GHz
37- 41 F5.1 mJy e_S(250) ? rms uncertainty on S(250)
43- 50 A8 --- Sess List of session numbers
53 A1 --- l_alf [>≲] Limit flag on spectral index
54- 58 F5.2 --- alf ? Spectral index (S(ν)∝ν-{alf})
60- 63 F4.2 --- e_alf ? rms uncertainty on spectral index
64 A1 --- u_alf [?] Uncertainty flag on alf
66- 98 A33 --- Rem Remarks
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Byte-per-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Star name
12- 22 A11 --- SpType MK spectral type
24- 28 F5.2 mas R(UD) Stellar radius
33- 37 A5 --- Refs References (1)
40 A1 --- l_S(250) Limit flag on S(250)
41- 45 F5.1 mJy S(250) Flux in continuum at 250GHz
48 A1 --- l_T(disk) Limit flag on disk temperature
49- 53 I5 K T(disk) Disk temperature
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Note (1): references are numbered as follows:
1 = Mozurkewich et al. 1991AJ....101.2207M 1991AJ....101.2207M
2 = di Benedetto & Rabbia 1987A&A...188..114D 1987A&A...188..114D
3 = Hutter et al. 1989ApJ...340.1103H 1989ApJ...340.1103H
4 = this article (see text)
5 = Fracassini et al. 1981A&AS...45..145F 1981A&AS...45..145F
6 = Hanbury Brown et al. 1974MNRAS.167..121H 1974MNRAS.167..121H
7 = di Benedetto & Foy 1986A&A...166..204D 1986A&A...166..204D
8 = Christou & Worden 1980AJ.....85..302C 1980AJ.....85..302C
9 = di Benedetto & Ferluga 1990A&A...236..449D 1990A&A...236..449D
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History:
* 14-Oct-1993: Original version from author
* 09-Apr-2008: homogenized the descriptions of the various tables
(End) Patricia Vannier, Francois Ochsenbein [CDS] 09-Apr-2008