PACS and SPIRE photometer maps of M33: First results of the HERschel M33 Extended Survey (HERM33ES)
Artikel i vetenskaplig tidskrift, 2010

Context. Within the framework of the HERM33ES key program, we are studying the star forming interstellar medium in the nearby, metal-poor spiral galaxy M33, exploiting the high resolution and sensitivity of Herschel. Aims. We use PACS and SPIRE maps at 100, 160, 250, 350, and 500 mu m wavelength, to study the variation of the spectral energy distributions (SEDs) with galacto-centric distance. Methods. Detailed SED modeling is performed using azimuthally averaged fluxes in elliptical rings of 2 kpc width, out to 8 kpc galacto-centric distance. Simple isothermal and two-component grey body models, with fixed dust emissivity index, are fitted to the SEDs between 24 mu m and 500 mu m using also MIPS/Spitzer data, to derive first estimates of the dust physical conditions. Results. The far-infrared and submillimeter maps reveal the branched, knotted spiral structure of M33. An underlying diffuse disk is seen in all SPIRE maps (250-500 mu m). Two component fits to the SEDs agree better than isothermal models with the observed, total and radially averaged flux densities. The two component model, with beta fixed at 1.5, best fits the global and the radial SEDs. The cold dust component clearly dominates; the relative mass of the warm component is less than 0.3% for all the fits. The temperature of the warm component is not well constrained and is found to be about 60 K +/- 10 K. The temperature of the cold component drops significantly from similar to 24 K in the inner 2 kpc radius to 13 K beyond 6 kpc radial distance, for the best fitting model. The gas-to-dust ratio for beta = 1.5, averaged over the galaxy, is higher than the solar value by a factor of 1.5 and is roughly in agreement with the subsolar metallicity of M33.

emission

nearby

milky-way

cold dust

infrared structure

dust

galaxies: individual: M33

cloud

galaxies: evolution

galaxies: evolution

galaxy m33

Local Group

extinction

galaxies:

star-formation

ISM

Författare

C. Kramer

Instituto de Radioastronomia Milimetrica

C. Buchbender

Instituto de Radioastronomia Milimetrica

E. M. Xilouris

National Observatory of Athens

M. Boquien

University of Massachusetts

J. Braine

Laboratoire d'Astrophysique de Bordeaux

D. Calzetti

University of Massachusetts

S. Lord

CalTech

B. Mookerjea

Tata Institute of Fundamental Research

G. Quintana-Lacaci

Instituto de Radioastronomia Milimetrica

M. Relano

University of Cambridge Institute of Astronomy

G. Stacey

Cornell University

F. Tabatabaei

Max Planck-institutet

S. Verley

Universidad de Granada

Susanne Aalto

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

S. Akras

National Observatory of Athens

M. Albrecht

Argelander Institut für Astronomie. Auf Dem Hügel 71

S. Anderl

Argelander Institut für Astronomie. Auf Dem Hügel 71

R. Beck

Max Planck-institutet

F. Bertoldi

Argelander Institut für Astronomie. Auf Dem Hügel 71

F. Combes

CNRS Centre National de la Recherche Scientifique

M. Dumke

European Southern Observatory Santiago

S. G. Burillo

Observatorio Astronomico Nacional

M. Gonzalez

Instituto de Radioastronomia Milimetrica

P. Gratier

Laboratoire d'Astrophysique de Bordeaux

R. Güsten

Max Planck-institutet

C. Henkel

Max Planck-institutet

F. P. Israel

Leiden University

B. Koribalski

Australia Telescope National Facility

A. Lundgren

European Southern Observatory Santiago

J. Martin-Pintado

CSIC-INTA - Centro de Astrobiologia (CAB)

M. Rollig

Universität zu Köln

E. Rosolowsky

University of British Columbia Okanagan

K. Schuster

Institut de RadioAstronomie Millimetrique (IRAM)

K. Sheth

CalTech

A. Sievers

Instituto de Radioastronomia Milimetrica

J. Stutzki

Universität zu Köln

R. P. J. Tilanus

F. F. S. van der Tak

SRON Netherlands Institute for Space Research

P. van der Werf

Leiden University

M. C. Wiedner

CNRS Centre National de la Recherche Scientifique

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 518 L67

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/201014613