2016MNRAS.457.1224L


Query : 2016MNRAS.457.1224L

2016MNRAS.457.1224L - Mon. Not. R. Astron. Soc., 457, 1224-1232 (2016/April-1)

Radio detections of southern ultracool dwarfs.

LYNCH C., MURPHY T., RAVI V., HOBBS G., LO K. and WARD C.

Abstract (from CDS):

We report the results of a volume-limited survey using the Australia Telescope Compact Array to search for transient and quiescent radio emission from 15 Southern hemisphere ultracool dwarfs. We detect radio emission from 2MASSW J0004348-404405 increasing the number of radio loud ultracool dwarfs to 22. We also observe radio emission from 2MASS J10481463-3956062 and 2MASSI J0339352-352544, two sources with previous radio detections. The radio emission from the three detected sources shows no variability or flare emission. Modelling this quiescent emission we find that it is consistent with optically thin gyrosynchrotron emission from a magnetosphere with an emitting region radius of (1-2)R*, magnetic field inclination 20°-80°, field strength ∼10-200 G, and power-law electron density ∼104-108/cm3. Additionally, we place upper limits on four ultracool dwarfs with no previous radio observations. This increases the number of ultracool dwarfs studied at radio frequencies to 222. Analysing general trends of the radio emission for this sample of 15 sources, we find that the radio activity increases for later spectral types and more rapidly rotating objects. Furthermore, comparing the ratio of the radio to X-ray luminosities for these sources, we find 2MASS J10481463-3956062 and 2MASSI J0339352-352544 violate the Gudel-Benz relation by more than two orders of magnitude.

Abstract Copyright: © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): stars: activity - brown dwarfs - stars: low-mass - stars: magnetic field - radio continuum: stars

Simbad objects: 17

goto Full paper

goto View the references in ADS

Number of rows : 17
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 L 362-29 B BD* 00 04 34.8671722377 -40 44 06.463544237       19.61 16.88 L5+L5 103 0
2 LP 881-64 ** 00 24 44.1774908692 -27 08 25.263232614   17.18 15.338 13.502 11.403 M5.5/6Ve+M8.5Ve+M9/9.5V 132 0
3 DENIS J025503.3-470049 BD* 02 55 03.6927058871 -47 00 51.356903955     22.921 19.906 17.454 L9 137 0
4 2MASS J02572581-3105523 BD* 02 57 25.8358051304 -31 05 52.195773867           L8.5 30 0
5 LEHPM 3396 LM* 03 34 12.2184742177 -49 53 32.027995648           M9 26 0
6 LP 944-20 LM* 03 39 35.2523500210 -35 25 43.641996333     18.69 16.39 13.288 M9.5Ve 281 0
7 2MASS J03400942-6724051 BD* 03 40 09.3513800352 -67 24 04.439306050           L7:: 10 0
8 ICRF J082526.8-501038 QSO 08 25 26.8673494560 -50 10 38.484054768   20.94       ~ 124 1
9 2MASS J08354256-0819237 BD* 08 35 42.5314423948 -08 19 23.372129099           L6.5 61 0
10 LP 666-9 LM* 08 53 36.1604798120 -03 29 32.197505547     18.959 16.781 14.487 M9Ve 240 0
11 LP 731-58 Er* 10 48 12.6142508200 -11 20 09.610693470     15.784 16.01 11.25 M6.5V 160 0
12 DENIS J104814.6-395606 LM* 10 48 14.5736104113 -39 56 06.842743867     17.532 15.051 12.67 M8.5Ve: 124 0
13 LP 851-346 PM* 11 55 42.8518932351 -22 24 58.797393048   19.6     13.203 M7.5V 26 0
14 LP 914-54 Er* 14 56 38.2634715567 -28 09 48.619153485     17.141 14.863 12.433 M7.0Ve 148 0
15 2MASSW J1507476-162738 BD* 15 07 47.6758255542 -16 27 40.113982846     22.136 18.928 16.579 L5V 186 0
16 2MASS J17502484-0016151 BD* 17 50 24.8108937456 -00 16 14.995437500       19.98 17.33 L5.5 39 0
17 ICRF J193925.0-634245 Sy2 19 39 25.0245304992 -63 42 45.640373400   18.87 18.37 17.64   ~ 1137 1

To bookmark this query, right click on this link: simbad:objects in 2016MNRAS.457.1224L and select 'bookmark this link' or equivalent in the popup menu


2023.01.30-06:27:47

© Université de Strasbourg/CNRS

    • Contact