Volume 372, Number 1, June II 2001
|Page(s)||241 - 244|
|Section||Interstellar and circumstellar matter|
|Published online||15 June 2001|
A BeppoSAX view of transient black hole candidates in quiescence
Osservatorio Astronomico di Brera, Via E. Bianchi 46, 23807 Merate (Lecco), Italy
2 Astrophysics Division, Space Science Department of ESA, ESTEC, PO Box 299, 2200 AG Noordwijk, The Netherlands
3 Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio Catone (Roma), Italy
Corresponding author: S. Campana, campana@mera te.mi.astro.it
Accepted: 2 April 2001
We report BeppoSAX observations of five transient black hole candidates during their quiescent phase. We confirm that these sources are X-ray faint, improving on and complementing existing upper limits. We derive 1-10 keV upper limits for GRO J0422+32, GRS 1009-45, 4U 1630-47 and XTE J1748-288, which range from to . We positively detect GS 2023+338. Its X-ray spectrum can be fit by a power law (photon index ) or a thermal bremsstrahlung (with keV), converting in both cases to a 1-10 keV unabsorbed luminosity of ~. These values are comparable to the ones derived during an ASCA observation in 1994, indicating that the source remains stable over a ~5 yr baseline.
Key words: binaries: general / black hole physics / X-rays: stars
© ESO, 2001
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.