THE ORIGIN OF THE 6.4 keV LINE EMISSION AND H{sub 2} IONIZATION IN THE DIFFUSE MOLECULAR GAS OF THE GALACTIC CENTER REGION
Journal Article
·
· Astrophysical Journal Letters
- I. E. Tamm Theoretical Physics Division of P. N. Lebedev Institute of Physics, Leninskii pr. 53, 119991 Moscow (Russian Federation)
- Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, IN2P3/CNRS and Univ Paris-Sud, F-91405 Orsay Campus (France)
- Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong)
- Astroparticule et Cosmologie, Universite Paris7/CNRS/CEA, Batiment Condorcet, F-75013 Paris (France)
We investigate the origin of the diffuse 6.4 keV line emission recently detected by Suzaku and the source of H{sub 2} ionization in the diffuse molecular gas of the Galactic center (GC) region. We show that Fe atoms and H{sub 2} molecules in the diffuse interstellar medium of the GC are not ionized by the same particles. The Fe atoms are most likely ionized by X-ray photons emitted by Sgr A* during a previous period of flaring activity of the supermassive black hole. The measured longitudinal intensity distribution of the diffuse 6.4 keV line emission is best explained if the past activity of Sgr A* lasted at least several hundred years and released a mean 2-100 keV luminosity {approx}> 10{sup 38} erg s{sup -1}. The H{sub 2} molecules of the diffuse gas cannot be ionized by photons from Sgr A*, because soft photons are strongly absorbed in the interstellar gas around the central black hole. The molecular hydrogen in the GC region is most likely ionized by low-energy cosmic rays, probably protons rather than electrons, whose contribution into the diffuse 6.4 keV line emission is negligible.
- OSTI ID:
- 22118674
- Journal Information:
- Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 771; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fe-K LINE PROBING OF MATERIAL AROUND THE ACTIVE GALACTIC NUCLEUS CENTRAL ENGINE WITH SUZAKU
A 3 pc SCALE JET-DRIVEN OUTFLOW FROM SGR A*
INTERACTING COSMIC RAYS WITH MOLECULAR CLOUDS: A BREMSSTRAHLUNG ORIGIN OF DIFFUSE HIGH-ENERGY EMISSION FROM THE INNER 2 Degree-Sign Multiplication-Sign 1 Degree-Sign OF THE GALACTIC CENTER
Journal Article
·
Wed Jan 19 23:00:00 EST 2011
· Astrophysical Journal
·
OSTI ID:21567614
A 3 pc SCALE JET-DRIVEN OUTFLOW FROM SGR A*
Journal Article
·
Wed Oct 10 00:00:00 EDT 2012
· Astrophysical Journal Letters
·
OSTI ID:22078499
INTERACTING COSMIC RAYS WITH MOLECULAR CLOUDS: A BREMSSTRAHLUNG ORIGIN OF DIFFUSE HIGH-ENERGY EMISSION FROM THE INNER 2 Degree-Sign Multiplication-Sign 1 Degree-Sign OF THE GALACTIC CENTER
Journal Article
·
Mon Dec 31 23:00:00 EST 2012
· Astrophysical Journal
·
OSTI ID:22167309