[工程科技]Near-Infrared Spectra of the Black Hole X-Ray Binary_ A0620-00.pdf

Near-Infrared Spectra of the Black Hole X-ray Binary A0620-00 Cynthia S. Froning1 cfroning@ Center for Astrophysics and Space Astronomy, University of Colorado, 7 593 UCB, Boulder, CO 80309-0593 0 0 2 Edward L. Robinson r p elr@ A 2 Department of Astronomy, University of Texas at Austin, Austin, TX 78712 ] and h p - Martin A. Bitner o r t mbitner@ s a [ Department of Astronomy, University of Texas at Austin, Austin, TX 78712 1 v 7 ABSTRACT 6 2 0 We present broadband NIR spectra of A0620-00 obtained with SpeX on the . 4 IRTF. The spectrum is characterized by a blue continuum on which are super- 0 7 imposed broad emission lines of H I and He II and a host of narrower absorption 0 lines of neutral metals and molecules. Spectral type standard star spectra scaled : v to the dereddened spectrum of A0620-00 in K exceed the A0620-00 spectrum in J i X and H for all stars of spectral type K7V or earlier, demonstrating that the donor r star, unless later than K7V, cannot be the sole NIR flux source in A0620-00. In a addition, the atomic absorption lines in the K3V spectrum are too weak with respect to those of A0620-00 even at 100% donor star contribution, restricting the spectral type of the donor star in A0620-00 to later than K3V. Comparison of the A0620-00 spectrum to scaled K st