THE WATER VAPOR SPECTRUM OF APM 08279+5255: X-RAY HEATING AND INFRARED PUMPING OVER HUNDREDS OF PARSECS

Journal Article · Thu Nov 10 04:00:00 EST 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/741/2/L37· OSTI ID:22047366

Bradford, C M; Bock, J J; Naylor, B J; Nguyen, H T; Zmuidzinas, J ^[1]; Bolatto, A D ^[2]; Maloney, P R; Aguirre, J E; Glenn, J; Kamenetzky, J ^[3]; Lupu, R; Scott, K ^[4]; Matsuhara, H ^[5]; Murphy, E J ^[6]

---

1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
2. Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)
3. Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80303 (United States)
4. Department of Physics, University of Pennsylvania, Philadelphia, PA 19104 (United States)
5. Institute for Space and Astronautical Science, Japan Aerospace and Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara 252-5210 (Japan)
6. Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

We present the rest-frame 200-320 {mu}m spectrum of the z = 3.91 quasar APM 08279+5255, obtained with Z-Spec at the Caltech Submillimeter Observatory. In addition to the J = 8 {yields} 7 to J = 13 {yields} 12 CO rotational transitions which dominate the CO cooling, we find six transitions of water originating at energy levels ranging up to 643 K. Most are first detections at high redshift, and we have confirmed one transition with CARMA. The CO cooling is well described by our X-ray dominated region (XDR) model, assuming L{sub 1-100keV} {approx} 1 Multiplication-Sign 10{sup 46} erg s{sup -1}, and that the gas is distributed over a 550-pc size scale, as per the now-favored {mu} = 4 lensing model. The total observed cooling in water corresponds to 6.5 Multiplication-Sign 10{sup 9} L{sub Sun }, comparable to that of CO. We compare the water spectrum with that of Mrk 231, finding that the intensity ratios among the high-lying lines are similar, but with a total luminosity scaled up by a factor of {approx}50. Using this scaling, we estimate an average water abundance relative to H{sub 2} of 1.4 Multiplication-Sign 10{sup -7}, a good match to the prediction of the chemical network in the XDR model. As with Mrk 231, the high-lying water transitions are excited radiatively via absorption in the rest-frame far-infrared, and we show that the powerful dust continuum in APM 08279+5255 is more than sufficient to pump this massive reservoir of warm water vapor.

• OSTI ID: 22047366
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 741; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
ASTROPHYSICS
CARBON MONOXIDE
COMPARATIVE EVALUATIONS
COOLING
COSMIC DUST
ENERGY LEVELS
GALAXIES
HEATING
HOT WATER
HYDROGEN
MOLECULES
QUASARS
RED SHIFT
WATER VAPOR
X RADIATION