Access to Astronomical Catalogues

← Click to display the menu
J/A+A/604/A65     Planck and Herschel images combination  (Abreu-Vicente+, 2017)

Fourier-space combination of Planck and Herschel images. Abreu-Vicente J., Stutz A., Henning T., Keto E., Ballesteros-Paredes J., Robitaille T. <Astron. Astrophys. 604, A65 (2017)> =2017A&A...604A..65A (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Photometry, millimetric/submm Keywords: submillimeter: ISM - infrared: ISM - techniques: image processing - ISM: structure Abstract: Herschel has revolutionized our ability to measure column densities (NH) and temperatures (T) of molecular clouds thanks to its far infrared multiwavelength coverage. However, the lack of a well defined background intensity level in the Herschel data limits the accuracy of the NH and T maps. We aim to provide a method that corrects the missing Herschel background intensity levels using the Planck model for foreground Galactic thermal dust emission. For the Herschel/PACS data, both the constant-offset as well as the spatial dependence of the missing background must be addressed. For the Herschel/SPIRE data, the constant-offset correction has already been applied to the archival data so we are primarily concerned with the spatial dependence, which is most important at 250um. We present a Fourier method that combines the publicly available Planck model on large angular scales with the Herschel images on smaller angular scales. We have applied our method to two regions spanning a range of Galactic environments: Perseus and the Galactic plane region around l=11° (HiGal-11). We post-processed the combined dust continuum emission images to generate column density and temperature maps. We compared these to previously adopted constant-offset corrections. We find significant differences (≳20%) over significant (∼155) arma3 of the maps, at low column densities (NH≲1022cm-2) and relatively high temperatures (T≳20K). We have also applied our method to synthetic observations of a simulated molecular cloud to validate our method. Our method successfully corrects the Herschel images, including both the constant-offset intensity level and the scale-dependent background variations measured by Planck. Our method improves the previous constant-offset corrections, which did not account for variations in the background emission levels. Description: We provide a method that combines the Herschel and Planck data in the Fourier space. Our method corrects the missing Herschel background intensity levels using the Planck model for foreground Galactic thermal dust emission. We apply our method to two regions spanning a range of Galactic environments: Perseus and the Galactic plane region around l=11°. We post-process the combined dust continuum emission images to generate column density and temperature maps. In this file we show the original Herschel and Planck products used to obtain our new combined images, also attached. We further provide the column density and temperature maps of Perseus and HiGaL 11 obtained through our new images. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file list.dat 166 40 List of fits files fits/* 0 40 Individual fits files
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- 35 I6 Kibyte size Size of FITS file 37- 73 A37 --- FileName Name of FITS file, in subdirectory fits (1) 75-166 A92 --- Title Title of the FITS file
Note (1):Fluxus are in Jy/arcsec2, column densities in cm-2 and temperatures in K.
Acknowledgements: Jorge Abreu-Vicente, abreu(at)mpia.de Max-Planck Institute for Astronomy
(End) J. Abreu-Vicente [Max-Planck Inst. Astron.], P. Vannier [CDS] 28-Jun-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

catalogue service

© UDS/CNRS

Contact