Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2025-01-06T02:47:51.616Z Has data issue: false hasContentIssue false
  • English
  • Français

Hat Creek HCO+ and HCN Observations of Sgr A

Published online by Cambridge University Press:  23 September 2016

M.C.H. Wright ,
J. M. Marr  and
D. C. Backer
M.C.H. Wright
Affiliation:
Radio Astronomy Laboratory, U.C. Berkeley, CA 94720
J. M. Marr
Affiliation:
Radio Astronomy Laboratory, U.C. Berkeley, CA 94720
D. C. Backer
Affiliation:
Radio Astronomy Laboratory, U.C. Berkeley, CA 94720

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We report aperture synthesis observations of the HCO+ and HCN J=1–0 molecular lines towards the Galactic center. These data complement existing HCN data and trace a dense molecular ring surrounding the ionized central 2 pc of the Galaxy. The new data are consistent with the model of a clumpy, almost complete ring which is inclined to the line of sight at 50 to 75 degrees. The same structure is seen in HCO+ and in HCN with the exception of an HCN feature at 60 to 100 km/s in the western part of the ring, which is not detected in HCO+ emission. The HCN and HCO+ are collisionally excited in clumps with densities around 10 cm and volume filling factor 1/3 to 1/30. H13 CN emission from the ring was detected at about 1/7 of the intensity of the HCN; the latter is optically thick and is mapping a combination of surface density and excitation temperature. The HCO+ emission shows deep absorption features associated with galactic structure along the line of sight. Absorption features corresponding to the 3 kpc arm, the inner disk and an expanding ring at −195 km/s can be seen in absorption against the Sgr A radio continuum.

Type
Sagittarius A West and the Circumnuclear Disk
Information
Symposium - International Astronomical Union , Volume 136: The Galactic Center , 1989 , pp. 407 - 410
Copyright
Copyright © Kluwer 1989 

References

Burton, W.B., and Liszt, H.S., 1978, Ap.J. 225, 815.Google Scholar
Gatley, I., Jones, T.I., Hyland, A.R., Wade, R., Geballe, T.R., and Krisciunas, K., 1986, M.N.R.A.S., 222, 299.CrossRefGoogle Scholar
Genzel, R., Watson, D.M., Crawford, M.K., and Townes, C.H., 1985, Ap.J., 297, 766.Google Scholar
Guesten, R., and Downes, D., 1981, Astr. Ap. 99, 27.Google Scholar
Guesten, R., Genzel, R., Wright, M.C.H., Jaffe, D.T, Stutzki, J., and Harris, A., 1987, Ap.J. 318, 124 Google Scholar
Harris, A.I., Jaffe, D.T., Silber, M., and Genzel, R., 1985, Ap.J. (Letters) 294, L93.Google Scholar
Liszt, H.S., and Burton, W.B., 1978, Ap.J. 226, 790.Google Scholar
Oort, J.H., 1977, Ann. Rev. Astr. Ap., 15, 295.Google Scholar
Wannier, P.G., and Linke, R.A., 1978, Ap.J., 226, 817.Google Scholar