X-ray Echoes of Infrared Flaring in Sgr A*

Mark Wardle*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution

Abstract

Sgr A* exhibits flaring in the infrared several times each day, occasionally accompanied by flaring in X-rays. The infrared flares are believed to arise through synchrotron emission from a transient population of accelerated electrons. The X-ray flaring has been interpreted as self-synchrotron-compton, inverse compton, or synchrotron emission associated with the transient electrons.

Here I consider the upscattering of infrared flare photons by relativistic thermal electrons in the accretion flow around Sgr A*. Typical profiles of electron density and temperature in the accretion flow are adopted and the X-ray light curves produced by upscattering of infrared flare photons by the accretion flow are computed.

Peak X-ray luminosities between 10(33) and 10(34) erg s(-1) are attained for a 10 mJy near-infrared flare, compatible with observed coincident infrared/X-ray flares from Sgr A*. Even if this process is not responsible for the observed flares it still presents a serious constraint on accretion flow models, which must avoid over-producing X-rays and also predicting observable time lags between flaring in infrared and in X-rays.

Future high-resolution infrared instrumentation will be able to place the location of the infrared flare and in coordination with the X-ray would severely constrain the disc geometry and the radial profiles of electron density and temperature in the accretion flow.

Original languageEnglish
Title of host publicationGalactic Center
Subtitle of host publicationA Window to the Nuclear Environment of Disk Galaxies
EditorsMark R. Morris, Q. Daniel Wang, Feng Yuan
Place of PublicationMichigan, US
PublisherAstronomical Society of the Pacific
Pages450-455
Number of pages6
ISBN (Electronic)9781583817599
ISBN (Print)9781583817582
Publication statusPublished - 2011
EventConference on the Galactic Center: A Window to the Nuclear Environment of Disk Galaxies - Shanghai
Duration: 19 Oct 200923 Oct 2009

Publication series

NameAstronomical Society of the Pacific Conference Series
PublisherAstronomical Society of the Pacific
Volume439

Conference

ConferenceConference on the Galactic Center: A Window to the Nuclear Environment of Disk Galaxies
CityShanghai
Period19/10/0923/10/09

Keywords

  • SAGITTARIUS-A
  • BLACK-HOLE
  • FLARES
  • EMISSION
  • MULTIWAVELENGTH
  • POLARIMETRY
  • MODELS

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