Chandra Observations of Diffuse X-Rays from the Sagittarius B2 Cloud

Abstract

We present the first Chandra results of the giant molecular cloud Sagittarius B2 (Sgr B2), located about 100 pc away from the Galactic center. Diffuse X-rays are clearly separated from one-and-a-half dozen resolved point sources. The X-ray spectrum exhibits pronounced iron K-shell transition lines at 6.40 keV (K alpha) and 7.06 keV (K beta), deep iron K-edge at 7.11 keV and large photo-electric absorption at low energy. The absorption-corrected X-ray luminosity is \sim 1 times 10^{35} erg s^{-1}, two orders of magnitude larger than the integrated luminosity of all the resolved point sources. The diffuse X-rays come mainly from the south-west half of the cloud with a concave-shape pointing to the Galactic center direction. These results strongly support the ASCA model that Sgr B2 is irradiated by an X-ray source at the Galactic center side.

11 pages, 3 figures, to be published in ApJ

References in corpus (1)

• ASCA Discovery of Diffuse 6.4 keV Emission Near the Sgr C Complex: A New X-ray Reflection Nebula

Cited by in corpus (58)

• Discovery of a superluminal Fe K echo at the Galactic Center: The glorious past of Sgr A* preserved by molecular clouds
• Iron line and diffuse hard X-ray emission from the starburst galaxy M82
• Iron and Nickel Line Diagnostics for the Galactic Center Diffuse Emission
• Hard X-ray view of the past activity of Sgr A* in a natural Compton mirror
• Interacting Cosmic Rays with Molecular Clouds: A Bremsstrahlung Origin of Diffuse High Energy Emission from the Inner 2deg by 1deg of the Galactic Center
• Fading hard X-ray emission from the Galactic Centre molecular cloud Sgr B2
• The Origin of Diffuse X-ray and $\gamma$-ray Emission from the Galactic Center Region: Cosmic Ray Particles
• XIPE: the X-ray Imaging Polarimetry Explorer
• Chandra Deep X-ray Observation of a Typical Galactic Plane Region and Near-Infrared Identification
• A RIAF Interpretation for the Past Higher Activity of the Galactic Center Black Hole and the 511 keV Annihilation Emission
• Fermi Bubbles Inflated by Winds Launched from the Hot Accretion Flow in Sgr A*
• Discovery of Variable Iron Fluorescence from Reflection Nebulae in the Galactic Center
• The Interaction of the Fermi Bubbles with the Milky Way's Hot Gas Halo
• The Origin of X-ray Emission from a Galactic Center Molecular Cloud: Low Energy Cosmic Ray Electrons
• Traces of past activity in the Galactic Centre
• Galactic Center Research: Manifestations of the Central Black Hole
• Herschel observations of the Sgr B2 cores: Hydrides, warm CO, and cold dust
• X-ray Diagnostics of Giant Molecular Clouds in the Galactic Center Region and Past Activity of Sgr A*
• The X-ray lightcurve of Sgr A* over the past 150 years inferred from Fe-Ka line reverberation in Galactic Centre molecular clouds
• Characteristics of Diffuse X-Ray Line Emission within 20 pc of the Galactic Center
• A Catalog of Diffuse X-ray-Emitting Features within 20 pc of Sgr A*: Twenty Pulsar Wind Nebulae?
• Time-Dependent Optical Spectroscopy of GRB 010222: Clues to the GRB Environment
• XMM-Newton observations of Sagittarius A East
• Hard X-ray Morphological and Spectral Studies of The Galactic Center Molecular Cloud Sgr B2: Constraining Past Sgr A* Flaring Activity
• Discoveries of Diffuse Iron Line Sources from the Sgr B Region
• Polarization of X-ray emission from the Sgr B2 cloud
• Observational evidence for gravitationally trapped massive axion(-like) particles
• A Time-Variable X-Ray Echo: Indications of a Past Flare of the Galactic-Center Black Hole
• Water Vapor around Sgr B2
• Radial Distribution of X-ray Point Sources near the Galactic Center
• X-ray Line Emission from Supernova Ejecta Fragments
• TeV Gamma-ray Observations of The Galactic Center Ridge By VERITAS
• Diffuse X-Ray Sky in the Galactic Center
• Suzaku Spectroscopy of an X-Ray Reflection Nebula and a New Supernova Remnant Candidate in the Sgr B1 Region
• An X-ray survey of the central molecular zone: variability of the Fe Ka emission line
• X-Ray Observation of Very High Energy Gamma-Ray Source, HESS J1745-303, with Suzaku
• X-ray Sources and Star Formation Activity in the Sgr B2 Cloud Observed with Chandra
• Interstellar gas in the Galaxy and the X-ray luminosity of Sgr A* in the recent past
• XMM-Newton study of the persistent X-ray source 1E1743.1-2843 located in the Galactic Center direction
• Highly ionized Fe K emission lines from the LINER galaxy M 81
• 74 MHz Nonthermal Emission from Molecular Clouds: Evidence for a Cosmic Ray Dominated Region at the Galactic Center
• X-Ray Reflection Nebulae with Large Equivalent Widths of Neutral Iron Ka Line in the Sgr C Region
• Interpretation of radio continuum and molecular line observations of Sgr B2: free-free and synchrotron emission, and implications for cosmic rays
• The Cosmic Ray Distribution in Sagittarius B
• Unusual diffuse X-ray source in the Galactic center region
• A past capture event at Sagittarius A* inferred from the fluorescent X-ray emission of Sagittarius B clouds
• XMM-Newton observations of the Galactic Centre Region - II: The soft thermal emission
• Examining molecular clouds in the Galactic Centre region using X-ray reflection spectra simulations
• The CARMA 3mm Survey of the Inner $0.7^{\circ }\times 0.4^{\circ }$ of the Central Molecular Zone
• Suzaku X-Ray Spectroscopy of a Peculiar Hot Star in the Galactic Center Region
• Reflection nebulae in the Galactic Center: the case for soft X-ray imaging polarimetry
• Multiple accretion events as a trigger for Sgr A* activity
• New Constraints on Cosmic Particle Populations at the Galactic Center using X-ray Observations of the Molecular Cloud Sagittarius B2
• The Galactic Center: Not an Active Galactic Nucleus
• Prospects for IXPE and eXTP polarimetric archaeology of the reflection nebulae in the Galactic center
• New X-ray views of the Galactic center observed with Suzaku
• Sgr A East and its surroundings observed in X-rays
• High Energy Emission from the Galactic Center