The Galactic Center: Not an Active Galactic Nucleus

Abstract

We present 10um-35um Spitzer spectra of the interstellar medium in the Central Molecular Zone (CMZ), the central 210 pc x 60 pc of the Galactic center (GC). We present maps of the CMZ in ionic and H2 emission, covering a more extensive area than earlier spectroscopic surveys in this region. The radial velocities and intensities of ionic lines and H2 suggest that most of the H2 0-0 S(0) emission comes from gas along the line-of-sight, as found by previous work. We compare diagnostic line ratios measured in the Spitzer Infrared Nearby Galaxies Survey (SINGS) to our data. Previous work shows that forbidden line ratios can distinguish star-forming galaxies from LINERs and AGNs. Our GC line ratios agree with star-forming galaxies and not with LINERs or AGNs.

Accepted for publication in the ApJ Supplement Series

References in corpus (13)

• A 100-parsec elliptical and twisted ring of cold and dense molecular clouds revealed by Herschel around the Galactic Center
• Chemical Abundances of Luminous Cool Stars in the Galactic Center from High-Resolution Infrared Spectroscopy
• Interacting Cosmic Rays with Molecular Clouds: A Bremsstrahlung Origin of Diffuse High Energy Emission from the Inner 2deg by 1deg of the Galactic Center
• The Origin of Diffuse X-ray and $\gamma$-ray Emission from the Galactic Center Region: Cosmic Ray Particles
• Point Sources from a Spitzer IRAC Survey of the Galactic Center
• Mid-Infrared Diagnostics of LINERs
• Nonthermal X-rays from low-energy cosmic rays: Application to the 6.4 keV line emission from the Arches cluster region
• Spitzer IRS Observations of the Galactic Center: Shocked Gas in the Radio Arc Bubble
• The X-ray lightcurve of Sgr A* over the past 150 years inferred from Fe-Ka line reverberation in Galactic Centre molecular clouds
• Massive Young Stellar Objects in the Galactic Center. I. Spectroscopic Identification from Spitzer/IRS Observations
• Coupling the dynamics and the molecular chemistry in the Galactic center
• Interstellar Extinction and Long-Period Variables in the Galactic Center
• Spatial and Temporal Variations of the Diffuse Iron 6.4 keV Line in the Galactic Center Region

Cited by in corpus (6)

• Spitzer Infrared Spectrograph Observations of the Galactic Center: Quantifying the Extreme Ultraviolet/so ft X-ray fluxes
• Reflection nebulae in the Galactic Center: the case for soft X-ray imaging polarimetry
• Massive Young Stellar Objects in the Galactic Center. II. Seeing Through the Ice-rich Envelopes
• Discovery of diffuse optical emission lines from the inner Galaxy: Evidence for LI(N)ER-like gas
• Hunting for Planetary Nebulae toward the Galactic Center
• Backlighting young stellar objects in the Central Molecular Zone: an ensemble-averaged abundance structure of methanol ices