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10.5. Short-term variability of Sagittarius A∗ at millimeter wavelengths

Published online by Cambridge University Press:  25 May 2016

T. Tsutsumi ,
T. Kawabata ,
A. Miyazaki  and
M. Tsuboi
T. Tsutsumi
Affiliation:
Nobeyama Radio Observatory, NAOJ, Minamimaki, Minamisaku, Nagano 384-13, Japan
T. Kawabata
Affiliation:
Bisei Astronomical Observatory, Okayama, Japan
A. Miyazaki
Affiliation:
Institute of Astrophysics and Planetary Science, Ibaraki University, Ibaraki, Japan
M. Tsuboi
Affiliation:
Institute of Astrophysics and Planetary Science, Ibaraki University, Ibaraki, Japan

Extract

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Time variability of Sgr A∗ at cm wavelengths is well known phenomenon and has been studied by several authors (e.g. Lo 1989; Zhao et al. 1992). On the other hand, variability at millimeter wavelengths is not well established. Wright & Backer (1993) reported significant flux variations at λ = 3.4mm in a month during the decay of a flare observed by the Very Large Array in 1990. However others found no variability at millimeter and submillimeter wavelengths (Gwinn et al. 1991; Zylka et al. 1995). Emission from extended component surrounding Sgr A∗ is significant even at millimeter wavelengths (e.g. Tsuboi et al. 1988), thus it is important to observe with a narrower beam to isolate the compact component for accurate measurement of variability of Sgr A∗. Here we present some results from an on-going millimeter monitoring program of Sgr A∗ with the Nobeyama Millimeter Array (NMA).

Type
Part III. Black Holes and Central Activity
Information
Symposium - International Astronomical Union , Volume 184: The Central Regions of the Galaxy and Galaxies , 1998 , pp. 439 - 440
Copyright
Copyright © Kluwer 1998 

References

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