Universität zu Köln

Moultaka, J., Eckart, A. and Muzic, K. (2015). ICE CUBES IN THE CENTER OF THE MILKY WAY: WATER-ICE AND HYDROCARBONS IN THE CENTRAL PARSEC. Astrophys. J., 806 (2). BRISTOL: IOP PUBLISHING LTD. ISSN 1538-4357

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Abstract

The close environment of the central supermassive black hole of our Galaxy has been studied thoroughly for decades in order to shed light on the behavior of the central regions of galaxies in general and of active galaxies in particular. The Galactic center (GC) has shown a wealth of structures on different scales with a complicated mixture of early-and late-type stars, ionized and molecular gas, dust, and winds. Here we aim to study. the distribution of water-ices and hydrocarbons in the central parsec, as well as along the line of sight. This study is made possible thanks to L-band spectroscopy. This spectral band, from 2.8 to 4.2 mu m, hosts important signatures of the circumstellar medium and interstellar dense and diffuse media among which deep absorption features are attributed to water-ices and hydrocarbons. We observed the GC in the L. band of the. ISAAC spectrograph located on the UT1/VLT ESO telescope. By mapping the central half parsec using 27 slit positions, we were able to build the first data cube of the region in this wavelength domain. Thanks to a calibrator spectrum of the foreground extinction in the L. band derived in a previous paper, we corrected our data cube for the line-of-sight extinction and validated our calibrator spectrum. The data show that a residual absorption due to water-ices and hydrocarbons is present in the corrected data cube. This suggests that the features are produced in the local environment of the GC, implying very low temperatures well below 80 K. This is in agreement with our finding of local CO ices in the central parsec described in Moultaka et al.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Moultaka, J. UNSPECIFIED UNSPECIFIED UNSPECIFIED Eckart, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Muzic, K. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-400986
DOI:	10.1088/0004-637X/806/2/202
Journal or Publication Title:	Astrophys. J.
Volume:	806
Number:	2
Date:	2015
Publisher:	IOP PUBLISHING LTD
Place of Publication:	BRISTOL
ISSN:	1538-4357
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language YOUNG STELLAR OBJECTS; DUST-EMBEDDED SOURCES; 3 MICRON SPECTRA; GALACTIC-CENTER; MU-M; PROPER MOTIONS; INTERSTELLAR EXTINCTION; ORGANIC MATERIAL; STAR; SPECTROSCOPY Multiple languages Astronomy & Astrophysics Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/40098