J/A+A/550/A12 NGC253 near-infrared H2 emission (Rosenberg+, 2013)
The excitation of near-infrared H2 emission in NGC 253.
Rosenberg M.J.F., van der Werf P.P., Israel F.P.
<Astron. Astrophys. 550, A12 (2013)>
=2013A&A...550A..12R 2013A&A...550A..12R
ADC_Keywords: Galaxies, Seyfert ; Molecular clouds ; Photometry, infrared
Keywords: ISM: molecules - ISM: lines and bands - galaxies: ISM -
galaxies: starburst - infrared: ISM
Abstract:
Because of its large angular size and proximity to the Milky Way, NGC
253, an archetypal starburst galaxy, provides an excellent laboratory
to study the intricacies of this intense episode of star formation.
We aim to characterize the excitation mechanisms driving the emission
in NGC 253. Specifically we aim to distinguish between shock
excitation and ultraviolet (UV) excitation as the dominant driving
mechanism, using Brγ, H2 and [FeII] as diagnostic emission
line tracers.
Description:
All observations were made with SINFONI at the ESO VLT. We observed in
the H, and K bands using a spatial pixel scale of 0.25" corresponding
to a field of view of 8" by 8" per frame and a spectral resolution
of 2000, 3000 and 4000 respectively, which corresponds to a velocity
resolution of 149.8, 99.9 and 74.9km/s. All science observations were
taken in the ABA'nodding mode (300s of object, 300s of sky, 300s of
object), where A' is slightly offset from A. The object exposures are
aligned and averaged during the reconstruction of the data cube. The
observations of NGC 253 were made in visitor mode on August 28th,
2005. In order to capture the full extent of the H2 emission,
consecutive frames were taken in the K band moving further away from
the center, along the disk until H2 was no longer detected. This
resulted in 6 separate pointings. Since there are also H2
transitions in the H band, a similar strategy was used, resulting in 4
separate pointings.
We used the standard reduction techniques of the SINFONI pipeline on
all observations, including corrections for flat field, dark current,
nonlinearity of pixels, distortion, and wavelength calibration. We
obtained the flux calibration and atmospheric corrections from
observations of a standard star, namely HR 2058 in the H band and
HD 20001 in the K band
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 120 5 List of FITS files
fits/* . 5 Individual FITS files
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 F5.3 arcsec/pix Scale Scale of the image
26- 28 I3 pix Nx Number of pixels along X-axis
29 A1 --- --- [x]
30- 32 I3 pix Ny Number of pixels along Y-axis
33 A1 --- --- [x]
34- 37 I4 --- Nz ? Number of slices
39- 53 A15 --- FileName Name of FITS file in subdirectory fits
55-120 A66 --- Title Title of the file
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Acknowledgements:
Marissa Rosenberg, mrose87(at)gmail.com
(End) Patricia Vannier [CDS] 11-Dec-2012