The Five College Radio Astronomy Observatory CO Survey of the Outer Galaxy

Heyer, M. H.; Brunt, Christopher M.; Snell, R. L.; Howe, J. E.; Schloerb, F. Peter; Carpenter, John M.

doi:10.1086/313086

Cited by 299 publications

(262 citation statements)

References 26 publications

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“…Heyer et al (1998) used the 15-element QUARRY array receiver to survey an 8¡-wide strip of latitude centered on the Perseus Arm between l \ 102¡ and 141¡. Since a large fraction of their survey overlaps our own halfbeamwidth survey, it is of interest to compare the two.…”

Section: Second Quadrantmentioning

confidence: 99%

The Milky Way in Molecular Clouds: A New Complete CO Survey

Dame

Hartmann

Thaddeus

2001

ApJ

2,113

178

2,713

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New large-scale CO surveys of the Ðrst and second Galactic quadrants and the nearby molecular cloud complexes in Orion and Taurus, obtained with the CfA 1.2 m telescope, have been combined with 31 other surveys obtained over the past two decades with that instrument and a similar telescope on Cerro Tololo in Chile, to produce a new composite CO survey of the entire Milky Way. The survey consists of 488,000 spectra that Nyquist or beamwidth sample the entire Galactic plane over a (1 8 ¡) strip 4¡È10¡ wide in latitude, and beamwidth or sample nearly all large local clouds at higher lati-1 4 ¡ tudes. Compared with the previous composite CO survey of Dame et al. (1987), the new survey has 16 times more spectra, up to 3.4 times higher angular resolution, and up to 10 times higher sensitivity per unit solid angle. Each of the component surveys was integrated individually using clipping or moment masking to produce composite spatial and longitude-velocity maps of the Galaxy that display nearly all of the statistically signiÐcant emission in each survey but little noise.The composite maps provide detailed information on individual molecular clouds, suggest relationships between clouds and regions widely separated on the sky, and clearly display the main structural features of the molecular Galaxy. In addition, since the gas, dust, and Population I objects associated with molecular clouds contribute to the Galactic emission in every major wavelength band, the precise kinematic information provided by the present survey will form the foundation for many large-scale Galactic studies.A map of molecular column density predicted from complete and unbiased far-infrared and 21 cm surveys of the Galaxy was used both to determine the completeness of the present survey and to extrapolate it to the entire sky at o b o \ 32¡. The close agreement of the observed and predicted maps implies that only D2% of the total CO emission at o b o \ 32¡ lies outside our current sampling, mainly in the regions of Chamaeleon and the Gum Nebula. Taking into account this small amount of unobserved emission, the mean molecular column density decreases from D3 ] 1020 cm~2 at o b o \ 5¡ to D0.1 ] 1020 cm~2 at o b o \ 30¡ ; this drop is D6 times steeper than would be expected from a planeparallel layer, but is consistent with recent measurements of the mean molecular column density at higher latitudes.The ratio of the predicted molecular column density map to the observed CO intensity map provides a calibration of the mass conversion factor Out of the Galactic plane, X shows little systematic variation with latitude from a mean value of (1.8^0.3) ] 1020 cm~2 K~1 km~1 s. Given the large sky area and large quantity of CO data analyzed, we conclude that this is the most reliable measurement to date of the mean X value in the solar neighborhood.

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Section: Second Quadrantmentioning

confidence: 99%

The Milky Way in Molecular Clouds: A New Complete CO Survey

Dame

Hartmann

Thaddeus

2001

ApJ

2,113

178

2,713

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“…A number of large CO line surveys along the Galactic Plane have been carried out in the past (see a review by Heyer & Dame 2015), such as the 12 CO (1-0) surveys at the Center-forAstrophysics (CfA) 1.2-meter telescope (Dame et al 2001) and the Five College Radio Astronomy Observatory (FCRAO) 14-meter telescope (Heyer et al 1998). These previous surveys also obtained large-field 12 CO images around Tycho's SNR, which provided complementary CO data in this work.…”

Section: Complementary Co Datamentioning

confidence: 99%

Large-field CO (1–0) observations toward the Galactic historical supernova remnants: a large cavity aroundTycho’s supernova remnant

Chen¹,

Xiong²,

Yang³

2017

A&A

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Context. The investigation of the interaction between the supernova remnants (SNRs) and interstellar gas is not only necessary to improve our knowledge of SNRs, but also to understand the nature of the progenitor systems. Aims. As a part of the Milky Way Imaging Scroll Painting CO line survey, the aim is to study the interstellar gas surrounding the Galactic historical SNRs. In this work, we present the CO results of Tycho's SNR. Methods. Using the 3×3 Superconducting Spectroscopic Array Receiver (SSAR) at the PMO 13.7-meter telescope, we performed large-field (3 • × 2 • ) and high-sensitivity CO (1-0) molecular line observations toward Tycho's SNR. Results. The CO observations reveal large molecular clouds, stream-like structures, and an inner rim around the remnant. We derived the basic properties (column density, mass, and kinematics) of these objects based on the CO observations. The large molecular clouds individually show an arc toward the remnant center, outlining a large cavity with radii of ∼ 0.3 • × 0.6 • (or 13 pc × 27 pc at a distance of 2.5 kpc) around the remnant. The CO line broadenings and asymmetries detected in the surrounding clouds, the observed expansion of the cavity, in concert with enhanced 12 CO (2-1)/(1-0) intensity ratio detected in previous studies, suggest the interaction of the large cavity with a wind in the region. After excluding the scenario of a large bubble produced by bright massive stars, we suggest that the large cavity could be explained by accretion wind from the progenitor system of Tycho's supernova. Nevertheless, the possibility of the random distribution of a large cavity around Tycho's SNR cannot be ruled out thus far. Further observations are needed to confirm the physical association of the large cavity with Tycho's SNR.

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“…Additional extensions to the GRS, in the first and second quadrants, toward the Galactic anticentre, also in 12 CO (J = 1−0), have been carried out with the FCRAO (Heyer et al 1998;Brunt et al, in prep.). The International Galactic Plane Survey (IGPS) has combined three interferometric 21 cm HI surveys at 45-60 resolution.…”

Section: Introductionmentioning

confidence: 99%

Hi-GAL, theHerschelinfrared Galactic Plane Survey: photometric maps and compact source catalogues

Molinari

Schisano

Elia

et al. 2016

A&A

235

272

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Aims. We present the first public release of high-quality data products (DR1) from Hi-GAL, the Herschel infrared Galactic Plane Survey. Hi-GAL is the keystone of a suite of continuum Galactic plane surveys from the near-IR to the radio and covers five wavebands at 70, 160, 250, 350 and 500 µm, encompassing the peak of the spectral energy distribution of cold dust for 8 < ∼ T < ∼ 50 K. This first Hi-GAL data release covers the inner Milky Way in the longitude range 68 • > ∼ > ∼ −70 • in a |b| ≤ 1 • latitude strip. Methods. Photometric maps have been produced with the ROMAGAL pipeline, which optimally capitalizes on the excellent sensitivity and stability of the bolometer arrays of the Herschel PACS and SPIRE photometric cameras. It delivers images of exquisite quality and dynamical range, absolutely calibrated with Planck and IRAS, and recovers extended emission at all wavelengths and all spatial scales, from the point-spread function to the size of an entire 2 • × 2 • "tile" that is the unit observing block of the survey. The compact source catalogues were generated with the CuTEx algorithm, which was specifically developed to optimise source detection and extraction in the extreme conditions of intense and spatially varying background that are found in the Galactic plane in the thermal infrared. Results. Hi-GAL DR1 images are cirrus noise limited and reach the 1σ-rms predicted by the Herschel Time Estimators for parallel-mode observations at 60 s −1 scanning speed in relatively low cirrus emission regions. Hi-GAL DR1 images will be accessible through a dedicated web-based image cutout service. The DR1 Compact Source Catalogues are delivered as single-band photometric lists containing, in addition to source position, peak, and integrated flux and source sizes, a variety of parameters useful to assess the quality and reliability of the extracted sources. Caveats and hints to help in this assessment are provided. Flux completeness limits in all bands are determined from extensive synthetic source experiments and greatly depend on the specific line of sight along the Galactic plane because the background strongly varies as a function of Galactic longitude. Hi-GAL DR1 catalogues contain 123210, 308509, 280685, 160972, and 85460 compact sources in the five bands.

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The Five College Radio Astronomy Observatory CO Survey of the Outer Galaxy

Cited by 299 publications

References 26 publications

The Milky Way in Molecular Clouds: A New Complete CO Survey

The Milky Way in Molecular Clouds: A New Complete CO Survey

Large-field CO (1–0) observations toward the Galactic historical supernova remnants: a large cavity aroundTycho’s supernova remnant

Hi-GAL, theHerschelinfrared Galactic Plane Survey: photometric maps and compact source catalogues

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