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J/A+A/612/A26       Deep HI observations of Leo T with WSRT  (Adams+, 2018)

Deep neutral hydrogen observations of Leo T with the Westerbork Synthesis Radio Telescope. Adams E.A.K, Oosterloo T.A <Astron. Astrophys. 612, A26 (2018)> =2018A&A...612A..26A (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Photometry, CCD ; H I data Keywords: galaxies: ISM - galaxies: dwarf - Local Group - radio lines: galaxies - galaxies: individual: Leo T - galaxies: star formation Abstract: Leo T is the lowest mass gas-rich galaxy currently known and studies of its gas content help us understand how such marginal galaxies survive and form stars. We present deep neutral hydrogen (HI) observations from the Westerbork Synthesis Radio Telescope in order to understand its HI distribution and potential for star formation. We find a larger HI line flux than the previously accepted value, resulting in a 50% larger HI mass of 4.1x105M. The additional HI flux is from low surface brightness emission that was previously missed; with careful masking this emission can be recovered even in shallower data.We perform a Gaussian spectral decomposition to find a cool neutral medium component (CNM) with a mass of 3.7x104M, or almost 10% of the total HI mass. Leo T has no HI emission extending from the main HI body, but there is evidence of interaction with the Milky Way circumgalactic medium in both a potential truncation of the HI body and the offset of the peak HI distribution from the optical center. The CNM component of Leo T is large when compared to other dwarf galaxies, even though Leo T is not currently forming stars and has a lower star formation efficiency than other gas-rich dwarf galaxies. However, the HI column density associated with the CNM component in Leo T is low. One possible explanation is the large CNM component is not related to star formation potential but rather a recent, transient phenomenon related to the interaction of Leo T with the Milky Way circumgalactic medium. Description: The final cleaned data cube for ten 12-hr WSRT tracks combined is presented, along with a total intensity, primary-beam corrected HI map (in units of 1020atoms/cm2) and moment one (velocity field) and moment two (velocity dispersion) maps, both in units of km/s. Objects: -------------------------------------------------- RA (2000) DE Designation(s) -------------------------------------------------- 09 34 53.4 +17 03 05 Leo T = NAME Leo T dSph -------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file list.dat 173 4 List of fits files fits/* 0 4 Individual fits images and data cube
See also: J/ApJ/756/108 : Variable stars in Leo T HST VI photometry (Clementini+, 2017) Byte-by-byte Description of file: list.dat
Bytes Format Units Label Explanations
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000) 10- 18 F9.5 deg DEdeg Declination of center (J2000) 20- 23 I4 --- Nx Number of pixels along X-axis 25- 28 I4 --- Ny Number of pixels along Y-axis 30- 32 I3 --- Nz ? Number of slices 34- 54 A21 --- Obs.Date Observation date (YYYY-MM-DDThh:mm:ss.s) 56- 63 F8.1 m/s HVel Heliocentric velocity, or lower value of the heliocentric velocity for the datacube 65- 70 I6 m/s BHVel ? Upper value of the heliocentric velocity interval for the datacube 72- 78 F7.3 m/s dHVel ? Heliocentric velocity resolution for the datacube 80- 85 I6 Kibyte size Size of FITS file 87-100 A14 --- FileName Name of FITS file, in subdirectory fits 102-173 A72 --- Title Title of the FITS file
Acknowledgements: Betsey Adams, adams(at)astron.nl
(End) Patricia Vannier [CDS] 18-Dec-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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