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A Sensitive Search for [N II]205 μm Emission in a z = 6.4 Quasar Host Galaxy

Walter, Fabian and Weiss, Axel and Riechers, Dominik A. and Carilli, Christopher L. and Bertoldi, Frank and Cox, Pierre and Menten, Karl M. (2009) A Sensitive Search for [N II]205 μm Emission in a z = 6.4 Quasar Host Galaxy. Astrophysical Journal Letters, 69 (1). L1-L4. ISSN 2041-8205. doi:10.1088/0004-637X/691/1/L1.

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We present a sensitive search for the 3P1 → 3P0 ground-state fine structure line at 205 μm of ionized nitrogen ([N II]205μm) in one of the highest-redshift quasars (J1148+5251 at z = 6.42) using the IRAM 30 m telescope. The line is not detected at a (3σ) depth of 0.47 Jy km s^−1, corresponding to a [N II]205μm luminosity limit of L[N II] < 4.0×10^8 L☉ and a L[N II]/LFIR ratio of < 2×10^−5. In parallel, we have observed the CO (J = 6–5) line in J1148+5251, which is detected at a flux level consistent with earlier interferometric observations. Using our earlier measurements of the [C II] 158 μm line strength, we derive an upper limit for the [N II]205μm/[C II] line luminosity ratio of ~1/10 in J1148+5251. Our upper limit for the [C II]/[N II]205μm ratio is similar to the value found for our Galaxy and M82 (the only extragalactic system where the [N II]205μm line has been detected to date). Given the nondetection of the [N II]205μm line we can only speculate whether or not high-z detections are within reach of currently operating observatories. However, [N II]205μm and other fine-structure lines will play a critical role in characterizing the interstellar medium at the highest redshifts (z > 7) using the Atacama Large Millimeter/submillimeter Array, for which the highly excited rotational transitions of CO will be shifted outside the accessible (sub-)millimeter bands.

Item Type:Article
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URLURL TypeDescription
Walter, Fabian0000-0003-4793-7880
Weiss, Axel0000-0003-4678-3939
Riechers, Dominik A.0000-0001-9585-1462
Carilli, Christopher L.0000-0001-6647-3861
Bertoldi, Frank0000-0002-1707-1775
Cox, Pierre0000-0003-2027-8221
Menten, Karl M.0000-0001-6459-0669
Additional Information:© 2009. The American Astronomical Society. Received 2008 August 21; accepted 2008 November 20; published 2008 December 29. Print publication: Issue 1 (2009 January 20). The authors thank Roberto Maiolino, Alberto Bolatto, and Helmut Wiesemeyer for useful comments on the manuscript. F.W. and D.R. acknowledge the hospitality of the Aspen Center for Physics, where parts of this manuscript were written. D.R. acknowledges support from NASA through Hubble Fellowship grant HST-HF-01212.01-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. C.C. acknowledges support from the Max-Planck-Gesellschaft and the Alexander von Humboldt-Stiftung through the Max-Planck-Forschungspreis 2005.
Funding AgencyGrant Number
NASA Hubble FellowshipHST-HF-01212.01-A
NASANAS 5-26555
Alexander von Humboldt FoundationUNSPECIFIED
Space Telescope Science InstituteUNSPECIFIED
Subject Keywords:cosmology: observations; galaxies: active; galaxies: formation; galaxies: high-redshift; galaxies: starburst; radio lines: galaxies
Issue or Number:1
Record Number:CaltechAUTHORS:WALapjl09
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12890
Deposited By: Archive Administrator
Deposited On:09 Jan 2009 01:01
Last Modified:08 Nov 2021 22:33

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