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CO(J = 1-0) Imaging of M51 with CARMA and the Nobeyama 45 m Telescope

Koda, Jin and Sawada, Tsuyoshi and Wright, Melvyn C. H. and Teuben, Peter and Corder, Stuartt A. and Patience, Jenny and Scoville, Nick and Donovan Meyer, Jennifer and Egusa, Fumi (2011) CO(J = 1-0) Imaging of M51 with CARMA and the Nobeyama 45 m Telescope. Astrophysical Journal Supplement Series, 193 (1). Art. No. 19. ISSN 0067-0049.

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We report the CO(J = 1-0) observations of the Whirlpool Galaxy M51 using both the Combined Array for Research in Millimeter Astronomy (CARMA) and the Nobeyama 45 m telescope (NRO45). We describe a procedure for the combination of interferometer and single-dish data. In particular, we discuss (1) the joint imaging and deconvolution of heterogeneous data, (2) the weighting scheme based on the root-mean-square (rms) noise in the maps, (3) the sensitivity and uv coverage requirements, and (4) the flux recovery of a combined map. We generate visibilities from the single-dish map and calculate the noise of each visibility based on the rms noise. Our weighting scheme, though it is applied to discrete visibilities in this paper, should be applicable to grids in uv space, and this scheme may advance in future software development. For a realistic amount of observing time, the sensitivities of the NRO45 and CARMA visibility data sets are best matched by using the single-dish baselines only up to 4-6 kλ (about 1/4-1/3 of the dish diameter). The synthesized beam size is determined to conserve the flux between the synthesized beam and convolution beam. The superior uv coverage provided by the combination of CARMA long baseline data with 15 antennas and NRO45 short spacing data results in the high image fidelity, which is evidenced by the excellent overlap between even the faint CO emission and dust lanes in an optical Hubble Space Telescope image and polycyclicaromatichydrocarbon emission in a Spitzer 8 μm image. The total molecular gas masses of NGC 5194 and 5195 (d = 8.2 Mpc) are 4.9 × 10^9 M_⊙ and 7.8 × 10^7 M_⊙, respectively, assuming the CO-to-H_2 conversion factor of X _(CO) = 1.8 × 10^(20) cm-2(K km s^(–1))^(–1). The presented images are an indication of the millimeter-wave images that will become standard in the next decade with CARMA and NRO45, and the Atacama Large Millimeter/Submillimeter Array.

Item Type:Article
Related URLs:
URLURL TypeDescription
Koda, Jin0000-0002-8762-7863
Scoville, Nick0000-0002-0438-3323
Donovan Meyer, Jennifer0000-0002-3106-7676
Additional Information:© 2011 American Astronomical Society. Received 2010 November 9; accepted 2011 February 1; published 2011 March 3. We thank Yasutaka Kurono for insightful comments on an early draft and the anonymous referee for useful comments. We also thank all the CARMA integration team members and the support staff at the Nobeyama Radio Observatory. The Nobeyama 45 m telescope is operated by the Nobeyama Radio Observatory, a branch of the National Astronomical Observatory of Japan. Support for CARMA construction was derived from the Gordon and Betty Moore Foundation, the Kenneth T. and Eileen L. Norris Foundation, the James S. McDonnell Foundation, the Associates of the California Institute of Technology, the University of Chicago, the States of California, Illinois, and Maryland, and the National Science Foundation. Ongoing CARMA development and operations are supported by the National Science Foundation under a cooperative agreement and by the CARMA partner universities. This research was partially supported by HST-AR-11261.01.
Funding AgencyGrant Number
Gordon and Betty Moore FoundationUNSPECIFIED
Kenneth T. and Eileen L. Norris FoundationUNSPECIFIED
James S. McDonnell FoundationUNSPECIFIED
Associates of the California Institute of TechnologyUNSPECIFIED
University of ChicagoUNSPECIFIED
State of CaliforniaUNSPECIFIED
State of Illinois UNSPECIFIED
State of MarylandUNSPECIFIED
CARMA partner universitiesUNSPECIFIED
Hubble Space Telescope (HST)HST-AR-11261.01
Subject Keywords:galaxies: individual (NGC 5194, NGC 5195, M51); techniques: image processing; techniques: interferometric
Issue or Number:1
Classification Code:PACS: 98.62.Hr; 95.85.Bh; 98.62.Bj
Record Number:CaltechAUTHORS:20110421-074713123
Persistent URL:
Official Citation:CO(J = 1-0) Imaging of M51 with CARMA and the Nobeyama 45 m Telescope Jin Koda, Tsuyoshi Sawada, Melvyn C. H. Wright, Peter Teuben, Stuartt A. Corder, Jenny Patience, Nick Scoville, Jennifer Donovan Meyer and Fumi Egusa doi: 10.1088/0067-0049/193/1/19
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:23403
Deposited By: Ruth Sustaita
Deposited On:21 Apr 2011 15:44
Last Modified:03 Oct 2019 02:46

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