Diffraction Limited Imaging Spectroscopy of the SgrA* Region using OSIRIS, a new Keck Instrument

Abstract

We present diffraction limited spectroscopic observations of an infrared flare associated with the radio source SgrA*. These are the first results obtained with OSIRIS, the new facility infrared imaging spectrograph for the Keck Observatory operated with the laser guide star adaptive optics system. After subtracting the spectrum of precursor emission at the location of Sgr A*, we find the flare has a spectral index of -2.6 +- 0.9. If we do not subtract the precursor light, then our spectral index is consistent with earlier observations by Ghez et al. (2005). All observations published so far suggest that the spectral index is a function of the flare's K-band flux.

paper accepted for publication in ApJ Letters

References in corpus (14)

• The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth
• Nonthermal Electrons in Radiatively Inefficient Accretion Flow Models of Sagittarius A*
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• SINFONI in the Galactic Center: young stars and IR flares in the central light month
• Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre
• Variable Infrared Emission from the Supermassive Black Hole at the Center of the Milky Way
• XMM-Newton observation of the brightest X-ray flare detected so far from SgrA*
• On The Nature of the Variable Infrared Emission from Sgr A*
• First Simultaneous NIR/X-ray Detection of a Flare from SgrA*
• The First Laser Guide Star Adaptive Optics Observations of the Galactic Center: Sgr A*'s Infrared Color and the Extended Red Emission in its Vicinity
• A New X-Ray Flare from the Galactic Nucleus Detected with the XMM-Newton Photon Imaging Cameras
• Variations in the spectral slope of Sgr A* during a NIR flare
• Electron Acceleration around the Supermassive Black Hole at the Galactic Center
• A dual emission mechanism in Sgr A*/L' ?

Cited by in corpus (22)

• The Galactic Center Massive Black Hole and Nuclear Star Cluster
• An X-ray, IR, and Submillimeter Flare of Sagittarius A*
• A Constant Spectral Index for Sagittarius A* During Infrared/X-ray Intensity Variations
• A polarised infrared flare from Sagittarius A* and the signatures of orbiting plasma hotspots
• Variability Timescale and Spectral Index of Sgr A* in the Near Infrared: Approximate Bayesian Computation Analysis of the Variability of the Closest Supermassive Black Hole
• Prospects for testing the nature of Sgr A*'s NIR flares on the basis of current VLT- and future VLTI-observations
• What is limiting near-infrared astrometry in the Galactic Center?
• Simultaneous NIR/sub-mm observation of flare emission from SgrA*
• Black Hole Shadow Image and Visibility Analysis of Sagittarius A*
• Rapid Variability of Sgr A* across the Electromagnetic Spectrum
• Concurrent X-ray, near-infrared, sub-millimeter, and GeV gamma-ray observations of Sgr A*
• The extreme luminosity states of Sagittarius A*
• General relativistic effects and the near-infrared and X-ray variability of Sgr A* I
• Multi-wavelength Variability of Sagittarius A* in July 2019
• Soft gamma-ray constraints on a bright flare from the Galactic Center supermassive black hole
• Astrophysics in 2006
• Correlation between Flux and Spectral Index during Flares in Sagittarius A*
• New Evidence for a Flux-independent Spectral Index of Sgr A* in the Near-infrared
• LGS AO Science Impact: Present and Future Perspectives
• LIINUS/SERPIL: a design study for interferometric imaging spectroscopy at the LBT
• The Galactic Center
• LIINUS/SERPIL: a design study for interferometric imaging spectroscopy at the LBT