The cosmic-ray and gas content of the Cygnus region as measured in γ-rays by the Fermi Large Area Telescope

被引：47

作者：

Ackermann, M. ^{[1
,2
]}

Ajello, M. ^{[1
,2
]}

Allafort, A. ^{[1
,2
]}

Baldini, L. ^{[3
]}

Ballet, J. ^{[4
]}

Barbiellini, G. ^{[5
,6
]}

Bastieri, D. ^{[7
,8
]}

Belfiore, A. ^{[9
]}

Bellazzini, R. ^{[3
]}

Berenji, B. ^{[1
,2
]}

Blandford, R. D. ^{[1
,2
]}

Bloom, E. D. ^{[1
,2
]}

Bonamente, E. ^{[10
,11
]}

Borgland, A. W. ^{[1
,2
]}

Bottacini, E. ^{[1
,2
]}

Bregeon, J. ^{[3
]}

Brigida, M. ^{[12
,13
,14
]}

Bruel, P. ^{[15
]}

Buehler, R. ^{[1
,2
]}

Buson, S. ^{[7
,8
]}

Caliandro, G. A. ^{[16
]}

Cameron, R. A. ^{[1
,2
]}

Caraveo, P. A. ^{[9
]}

Casandjian, J. M. ^{[4
]}

Cecchi, C. ^{[10
,11
]}

Chekhtman, A. ^{[17
]}

Ciprini, S. ^{[11
,18
]}

Claus, R. ^{[1
,2
]}

Cohen-Tanugi, J. ^{[19
]}

de Angelis, A. ^{[20
,21
]}

de Palma, F. ^{[12
,13
,14
]}

Dermer, C. D. ^{[22
]}

do Couto e Silva, E. ^{[1
,2
]}

Drell, P. S. ^{[1
,2
]}

Dumora, D. ^{[23
]}

Favuzzi, C. ^{[12
,13
,14
]}

Fegan, S. J. ^{[15
]}

Focke, W. B. ^{[1
,2
]}

Fortin, P. ^{[15
]}

Fukazawa, Y. ^{[24
]}

Fusco, P. ^{[12
,13
,14
]}

Gargano, F. ^{[14
]}

Germani, S. ^{[10
,11
]}

Giglietto, N. ^{[12
,13
,14
]}

Giordano, F. ^{[12
,13
,14
]}

Giroletti, M. ^{[25
]}

Glanzman, T. ^{[1
,2
]}

Godfrey, G. ^{[1
,2
]}

Grenier, I. A. ^{[4
]}

Guillemot, L.

机构：

[1] Stanford Univ, Dept Phys, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA

[2] Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA

[3] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy

[4] Univ Paris Diderot, CEA Saclay, Serv Astrophys, Lab AIM,CEA,IRFU,CNRS, F-91191 Gif Sur Yvette, France

[5] Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy

[6] Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy

[7] Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy

[8] Univ Padua, Dipartimento Fis G Galilei, I-35131 Padua, Italy

[9] INAF Ist Astrofis Spaziale & Fis Cosm, I-20133 Milan, Italy

[10] Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy

[11] Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy

[12] Univ Bari, Dipartimento Fis M Merlin, I-70126 Bari, Italy

[13] Politecn Bari, Dipartimento Fis M Merlin, I-70126 Bari, Italy

[14] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy

[15] Ecole Polytech, CNRS, IN2P3, Lab Leprince Ringuet, F-91128 Palaiseau, France

[16] Inst Ciencies Espai IEEE CSIC, Barcelona 08193, Spain

[17] Artep Inc, Ellicott City, MD 21042 USA

[18] ASI Sci Data Ctr, I-00044 Rome, Italy

[19] Univ Montpellier 2, CNRS, IN2P3, Lab Univers & Particules Montpellier, Montpellier, France

[20] Univ Udine, Dipartimento Fis, I-33100 Udine, Italy

[21] Ist Nazl Fis Nucl, Sez Trieste, Grp Collegato Udine, I-33100 Udine, Italy

[22] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA

[23] Univ Bordeaux 1, CNRS, IN2P3, Ctr Etud Nucl Bordeaux Gradignan, F-33175 Gradignan, France

[24] Hiroshima Univ, Dept Phys Sci, Hiroshima 7398526, Japan

[25] INAF Ist Radioastron, I-40129 Bologna, Italy

[26] Univ Alabama, CSPAR, Huntsville, AL 35899 USA

[27] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA

[28] Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland

[29] Ibaraki Univ, Coll Sci, Bunkyo Ku, Mito, Ibaraki 3108512, Japan

[30] Waseda Univ, Res Inst Sci & Engn, Shinjuku Ku, Tokyo 1698555, Japan

[31] IRAP, CNRS, F-31028 Toulouse 4, France

[32] Univ Toulouse, UPS, OMP, IRAP, Toulouse, France

[33] Kyoto Univ, Yukawa Inst Theoret Phys, Sakyo Ku, Kyoto 6068502, Japan

[34] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany

[35] Univ Maryland, Dept Phys, College Pk, MD 20742 USA

[36] Univ Maryland, Dept Astron, College Pk, MD 20742 USA

[37] Ist Nazl Fis Nucl, Sez Roma Tor Vergata, I-00133 Rome, Italy

[38] Boise State Univ, Dept Phys, Boise, ID 83725 USA

[39] Hiroshima Univ, Hiroshima Astrophys Sci Ctr, Hiroshima 7398526, Japan

[40] JAXA, Inst Space & Astronaut Sci, Chuo Ku, Sagamihara, Kanagawa 2525210, Japan

[41] Univ Denver, Dept Phys & Astron, Denver, CO 80208 USA

[42] Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany

[43] George Mason Univ, Coll Sci, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA

[44] Leopold Franzens Univ Innsbruck, Inst Astro & Teilchenphys, A-6020 Innsbruck, Austria

[45] Leopold Franzens Univ Innsbruck, Inst Theoret Phys, A-6020 Innsbruck, Austria

[46] Univ Calif Santa Cruz, Dept Phys, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA

[47] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA

[48] NYCB Real Time Comp Inc, Lattingtown, NY 11560 USA

[49] Ohio State Univ, Dept Phys, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA

[50] ICREA, Barcelona, Spain

来源：

ASTRONOMY & ASTROPHYSICS | 2012年 / 538卷

基金：

加拿大自然科学与工程研究理事会; 美国国家航空航天局; 瑞典研究理事会;

关键词：

ISM: abundances; ISM: clouds; cosmic rays; gamma rays: ISM; BLIND FREQUENCY SEARCHES; GALACTIC PLANE SURVEY; MILKY-WAY; SUPERNOVA REMNANT; INFRARED-EMISSION; MOLECULAR CLOUDS; DARK GAS; OUTER GALAXY; X-RAY; H-I;

D O I：

10.1051/0004-6361/201117539

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Context. The Cygnus region hosts a giant molecular-cloud complex that actively forms massive stars. Interactions of cosmic rays with interstellar gas and radiation fields make it shine at gamma-ray energies. Several gamma-ray pulsars and other energetic sources are seen in this direction. Aims. In this paper we analyze the gamma-ray emission measured by the Fermi Large Area Telescope (LAT) in the energy range from 100 MeV to 100 GeV in order to probe the gas and cosmic-ray content on the scale of the whole Cygnus complex. The gamma-ray emission on the scale of the central massive stellar clusters and from individual sources is addressed elsewhere. Methods. The signal from bright pulsars is greatly reduced by selecting photons in their off-pulse phase intervals. We compare the diffuse gamma-ray emission with interstellar gas maps derived from radio/mm-wave lines and visual extinction data. A general model of the region, including other pulsars and gamma-ray sources, is sought. Results. The integral HI emissivity above 100 MeV averaged over the whole Cygnus complex amounts to [2.06 +/- 0.11 (stat.) (+0.15)(-0.84) (syst.)] x 10(-26) photons s(-1) sr(-1) H-atom(-1), where the systematic error is dominated by the uncertainty on the HI opacity to calculate its column densities. The integral emissivity and its spectral energy distribution are both consistent within the systematics with LAT measurements in the interstellar space near the solar system. The average X-CO = N(H-2)/W-CO ratio is found to be [1.68 +/- 0.05 (stat.) (+0.87)(-0.10) (H I opacity)] x 10(20) molecules cm(-2) (K km s(-1))(-1), consistent with other LAT measurements in the Local Arm. We detect significant gamma-ray emission from dark neutral gas for a mass corresponding to similar to 40% of what is traced by CO. The total interstellar mass in the Cygnus complex inferred from its gamma-ray emission amounts to 8 (+5)(-1) x 10(6) M-circle dot at a distance of 1.4 kpc. Conclusions. Despite the conspicuous star formation activity and high masses of the interstellar clouds, the cosmic-ray population in the Cygnus complex averaged over a few hundred parsecs is similar to that of the local interstellar space.

引用

页数：15

共 72 条

[21] SURVEY OF INTER-STELLAR H-I FROM L-ALPHA ABSORPTION-MEASUREMENTS .2. [J].

BOHLIN, RC ;

SAVAGE, BD ;

DRAKE, JF .

ASTROPHYSICAL JOURNAL, 1978, 224 (01) :132-142

[22]

Camilo F., 2011, APJ IN PRESS

[23] THE RELATIONSHIP BETWEEN INFRARED, OPTICAL, AND ULTRAVIOLET EXTINCTION [J].

CARDELLI, JA ;

CLAYTON, GC ;

MATHIS, JS .

ASTROPHYSICAL JOURNAL, 1989, 345 (01) :245-256

[24] THE X-RAY SUPERBUBBLE IN CYGNUS [J].

CASH, W ;

CHARLES, P ;

BOWYER, S ;

WALTER, F ;

GARMIRE, G ;

RIEGLER, G .

ASTROPHYSICAL JOURNAL, 1980, 238 (02) :L71-L76

[25]

Cordes J. M., 2002, ARXIVASTROPH0207156V

[26]

Dame T. M., 2011, ARXIV11011499

[27] The milky way in molecular clouds: A new complete CO survey [J].

Dame, TM ;

Hartmann, D ;

Thaddeus, P .

ASTROPHYSICAL JOURNAL, 2001, 547 (02) :792-813

[28] THE OUTER DISK OF THE MILKY WAY SEEN IN λ21 cm ABSORPTION [J].

Dickey, John M. ;

Strasser, Simon ;

Gaensler, B. M. ;

Haverkorn, Marijke ;

Kavars, Dain ;

McClure-Griffiths, N. M. ;

Stil, Jeroen ;

Taylor, A. R. .

ASTROPHYSICAL JOURNAL, 2009, 693 (02) :1250-1260

[29] A full-sky Hα template for microwave foreground prediction [J].

Finkbeiner, DP .

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2003, 146 (02) :407-415

[30] The structure of molecular clouds - II. Column density and mass distributions [J].

Froebrich, Dirk ;

Rowles, Jonathan .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2010, 406 (02) :1350-1357

← 1 2 3 4 5 6 7 8 →