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J/A+A/615/A158   Data cubes of observed species toward Messier 8 (Tiwari+, 2018)

Unveiling the remarkable photodissociation region of Messier 8. Tiwari M., Menten K.M., Wyrowski F., Perez-Beaupuits J.P., Wiesemeyer H., Gusten R., Klein B., Henkel C. <Astron. Astrophys. 615, A158 (2018)> =2018A&A...615A.158T (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Interstellar medium ; Stars, bright Keywords: ISM: general - ISM: individual objects: M8 - submillimeter: ISM - HII regions - ISM: clouds Abstract: Messier 8 (M8) is one of the brightest HII regions in the sky. We collected an extensive dataset comprising multiple submillimeter spectral lines from neutral and ionized carbon and from CO. Based on this dataset, we aim to understand the morphology of M8 and that of its associated photodissociation region (PDR) and to carry out a quantitative analysis of the physical conditions of these regions such as kinetic temperatures and volume densities. We used the Stratospheric Observatory For Infrared Astronomy (SOFIA), the Atacama Pathfinder Experiment (APEX) 12m, and the Institut de Radioastronomie Millimetrique (IRAM) 30m telescopes to perform a comprehensive imaging survey of the emission from the fine structure lines of CII and CI and multiple rotational transitions of carbon monoxide (CO) isotopologs within 1.3x1.3pc around the dominant Herschel 36 (Her 36) system, which is composed of at least three massive stars. To further explore the morphology of the region, we compared archival infrared, optical, and radio images of the nebula with our newly obtained fine structure line and CO data, and in particular with the velocity information these data provide. We performed a quantitative analysis, using both LTE and non-LTE methods to determine the abundances of some of the observed species, kinetic temperatures, and volume densities. Bright CO, CII and CI emission have been found toward the HII region and the PDR in M8. Our analysis places the bulk of the molecular material in the background of the nebulosity illuminated by the bright stellar systems Her 36 and 9 Sagitarii. Since the emission from all observed atomic and molecular tracers peaks at or close to the position of Her 36, we conclude that the star is still physically close to its natal dense cloud core and heats it. A veil of warm gas moves away from Her 36 toward the Sun and its associated dust contributes to the foreground extinction in the region. One of the most prominent star forming regions in M8, the Hourglass Nebula, is particularly bright due to cracks in this veil close to Her 36. We obtain H2 densities ranging from ∼104-106cm-3 and kinetic temperatures of 100-150K in the bright PDR caused by Her 36 using radiative transfer modeling of various transitions of CO isotopologs. Description: Data cubes of the observed CII, CI and various CO rotational transitions toward M8. They contain both temperature and velocity information of the CII, CI and CO emission in a region ∼120"x120" around the bright stellar system Herschel 36. Objects: ------------------------------------------------- RA (2000) DE Designation(s) ------------------------------------------------- 18 03 37 -24 23.2 M8 = NAME Lagoon Nebula ------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file list.dat 112 16 List of fits data cubes fits/* 0 16 Individual fits data cubes
See also: J/A+A/395/499 : XMM observations in M8 and NGC6530 (Rauw+, 2002) J/MNRAS/407/1170 : IRAC photometry of M8 (Kumar+, 2010) J/MNRAS/453/1026 : Lagoon Nebula M8 T tauri accretion rates (Kalari+, 2015) J/A+A/604/A135 : Dynamics of ionized and neutral gas in M8 (Damiani+, 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- 21 I2 --- Nx Number of pixels along X-axis 23- 24 I2 --- Ny Number of pixels along Y-axis 26- 29 I4 --- Nz Number of slices 31- 38 F8.1 km/s bVRAD Lower value of radial velocity interval 40- 47 F8.1 km/s BVRAD Upper value of radial velocity interval 49- 57 F9.4 km/s dVRAD Radial velocity resolution 59- 63 I5 Kibyte size Size of FITS file 65- 79 A15 --- FileName Name of FITS file, in subdirectory fits 81-112 A32 --- Title Title of the FITS file
Acknowledgements: Maitraiyee Tiwari, mtiwari(at)
(End) Maitraiyee Tiwari [MPIfR, Germany], Patricia Vannier [CDS] 31-Jul-2018
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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