On the Nature of Ultraluminous X-Ray Sources, Or What a Black Hole Should Look Like

PDF Version Also Available for Download.

Description

We derive the luminosity-temperature relation for the accreting black holes (BHs). At the accretion rates below the critical Eddington, the BHs are described by the standard Shakura-Sunyaev model resulting in the L {infinity} T{sup 4} {infinity} M relation. At super-Eddington rates, {dot m} = {dot M}/{dot M}{sub Edd} >> 1, a strong outflow forms within the spherization radius R{sub sp} {infinity} {dot M}. If the angular momentum of the outflowing matter is conserved and typical outflow velocities are of the order of Keplerian, the wind occupies 50-85 per cent of the sky as viewed from the BH, while the region ... continued below

Physical Description

5 pages

Creation Information

Poutanen, Juri; /Oulu U. /KIPAC, Menlo Park; Fabrika, Sergei; /Stavropol, Astrophys. Observ.; Butkevich, Alexey G.; /Oulu U. /Pulkovo Observ., St. Petersburg et al. September 18, 2006.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

We derive the luminosity-temperature relation for the accreting black holes (BHs). At the accretion rates below the critical Eddington, the BHs are described by the standard Shakura-Sunyaev model resulting in the L {infinity} T{sup 4} {infinity} M relation. At super-Eddington rates, {dot m} = {dot M}/{dot M}{sub Edd} >> 1, a strong outflow forms within the spherization radius R{sub sp} {infinity} {dot M}. If the angular momentum of the outflowing matter is conserved and typical outflow velocities are of the order of Keplerian, the wind occupies 50-85 per cent of the sky as viewed from the BH, while the region around the rotation axis remains transparent. The bolometric luminosity in such a case is known to exceed the Eddington luminosity by a factor 1 + ln {dot m} and the observed luminosity is 2-7 times higher because of geometrical beaming. An edge-on observer sees only the soft emission from the extended envelope, with the photosphere radius exceeding R{sub sp} by orders of magnitude. The photosphere temperature follows the T{sub ph} {infinity} {dot M}{sup -3/4} or {dot M}{sup -1} relation depending on the velocity profile at R > R{sub sp} (constant velocity or a Keplerian profile). The resulting L-T{sub ph} dependence is consistent with that observed in the super-Eddington accreting BHs SS 433 and V4641 Sgr. A face-on observer has a direct view of the inner hot accretion disc which in stellar-mass BHs has temperature T{sub max} of a few keV. The effective temperature depends on radius as {infinity} R{sup -1/2} (up to the spherization radius) and the emitted spectrum is a power-law F{sub E} {infinity} E{sup -1} extending from {approx} 3T{sub max} down to the temperature at the spherization radius T{sub sp} {approx} {dot m}{sup -1/2} keV. It continues further as a power-law F{sub E} {infinity} E{sup 1/3} to the photospheric temperature T{sub ph}. We associate T{sub max} with a few keV spectral components and T{sub sp} with the soft, 0.1-0.2 keV components observed in the ultraluminous X-ray sources (ULX). The strong outflows combined with the large intrinsic X-ray luminosity of the central BH explain naturally the presence of the photoionized nebulae around ULX. An excellent agreement between the model and the observational data on ULX strongly argues in favour of ULX being super-critically accreting, stellar-mass BHs similar to SS 433, but viewed along the symmetry axis.

Physical Description

5 pages

Source

  • Journal Name: Submitted to Mon.Not.Roy.Astron.Soc.

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: SLAC-PUB-12118
  • Grant Number: AC02-76SF00515
  • Office of Scientific & Technical Information Report Number: 891858
  • Archival Resource Key: ark:/67531/metadc884011

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • September 18, 2006

Added to The UNT Digital Library

  • Sept. 21, 2016, 2:29 a.m.

Description Last Updated

  • Dec. 6, 2016, 2:28 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 1

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Poutanen, Juri; /Oulu U. /KIPAC, Menlo Park; Fabrika, Sergei; /Stavropol, Astrophys. Observ.; Butkevich, Alexey G.; /Oulu U. /Pulkovo Observ., St. Petersburg et al. On the Nature of Ultraluminous X-Ray Sources, Or What a Black Hole Should Look Like, article, September 18, 2006; [Menlo Park, California]. (digital.library.unt.edu/ark:/67531/metadc884011/: accessed December 13, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.