scholarly journals Near- and mid-infrared colours of star-forming galaxies in European Large Area ISO Survey fields

2002 ◽  
Vol 337 (3) ◽  
pp. 1043-1058 ◽  
Author(s):  
P. Vaisanen ◽  
T. Morel ◽  
M. Rowan-Robinson ◽  
S. Serjeant ◽  
S. Oliver ◽  
...  
Keyword(s):  
2020 ◽  
Vol 639 ◽  
pp. A80
Author(s):  
Xiao-Na Sun ◽  
Rui-Zhi Yang ◽  
Yun-Feng Liang ◽  
Fang-Kun Peng ◽  
Hai-Ming Zhang ◽  
...  

We report the detection of high-energy γ-ray signal towards the young star-forming region, W40. Using 10-yr Pass 8 data from the Fermi Large Area Telescope (Fermi-LAT), we extracted an extended γ-ray excess region with a significance of ~18σ. The radiation has a spectrum with a photon index of 2.49 ± 0.01. The spatial correlation with the ionized gas content favors the hadronic origin of the γ-ray emission. The total cosmic-ray (CR) proton energy in the γ-ray production region is estimated to be the order of 1047 erg. However, this could be a small fraction of the total energy released in cosmic rays (CRs) by local accelerators, presumably by massive stars, over the lifetime of the system. If so, W40, together with earlier detections of γ-rays from Cygnus cocoon, Westerlund 1, Westerlund 2, NGC 3603, and 30 Dor C, supports the hypothesis that young star clusters are effective CR factories. The unique aspect of this result is that the γ-ray emission is detected, for the first time, from a stellar cluster itself, rather than from the surrounding “cocoons”.


2009 ◽  
Vol 698 (1) ◽  
pp. 488-501 ◽  
Author(s):  
Esteban F. E. Morales ◽  
Diego Mardones ◽  
Guido Garay ◽  
Kate J. Brooks ◽  
Jaime E. Pineda

2021 ◽  
Vol 21 (10) ◽  
pp. 263
Author(s):  
Yun-Chuan Xiang ◽  
Ze-Jun Jiang ◽  
Yun-Yong Tang

Abstract In this work, we reanalyzed 11 years of spectral data from the Fermi Large Area Telescope (Fermi-LAT) of currently observed starburst galaxies (SBGs) and star-forming galaxies (SFGs). We used a one-zone model provided by NAIMA and the hadronic origin to explain the GeV observation data of the SBGs and SFGs. We found that a protonic distribution of a power-law form with an exponential cutoff can explain the spectra of most SBGs and SFGs. However, it cannot explain the spectral hardening components of NGC 1068 and NGC 4945 in the GeV energy band. Therefore, we considered the two-zone model to well explain these phenomena. We summarized the features of two model parameters, including the spectral index, cutoff energy, and proton energy budget. Similar to the evolution of supernova remnants (SNRs) in the Milky Way, we estimated the protonic acceleration limitation inside the SBGs to be the order of 102 TeV using the one-zone model; this is close to those of SNRs in the Milky Way.


2006 ◽  
Vol 2 (S237) ◽  
pp. 412-412
Author(s):  
Marcello Felli ◽  
Fabrizio Massi ◽  
Riccardo Cesaroni

AbstractThe star forming region S235A-B has been studied at high resolution with radio (IRAM Interferometer and VLA) and infrared (JCMT and Spitzer) observations. The region was mapped in HCO+, C34S, H2CS, SO2 and CH3CN as well as in the 1.2 and 3.3 continuum, in the cm continuum at 6, 3.6, 1.3 and 0.7 cm and in the 22 GHz water maser line, in the far infrared at 450 and 850 μm and in the mid infrared from 3.6 to 8 μm. Finally, use was made of the Medicina water maser patrol, from 1987 to 2005, to study the maser variability.


2001 ◽  
Vol 205 ◽  
pp. 224-227
Author(s):  
Jean L. Turner

Subarcsecond radio and infrared observations reveal a class of luminous, obscured, optically thick HII regions associated with extremely large young clusters in nearby starburst galaxies. VLA images show bright radio nebulae with ne ∼ 104 cm−3, densities characteristic of young Galactic compact HII regions. Excitation of the nebulae requires the presence of several thousand O stars within regions of 1-10 pc extent, corresponding to clusters containing 105–106 stars. The compact nebulae are also bright in the mid-infrared, and can for significant fractions of not only the total IR luminosity, but also the total bolometric luminosity, of the parent galaxies. The prototype for these “supernebulae” is the large, obscured cluster in the dwarf galaxy NGC 5253.


2012 ◽  
Vol 751 (2) ◽  
pp. 126 ◽  
Author(s):  
S. Starikova ◽  
S. Berta ◽  
A. Franceschini ◽  
L. Marchetti ◽  
G. Rodighiero ◽  
...  

2015 ◽  
Vol 454 (2) ◽  
pp. 1573-1584 ◽  
Author(s):  
Seong Jin Kim ◽  
Hyung Mok Lee ◽  
Woong-Seob Jeong ◽  
Tomotsugu Goto ◽  
Hideo Matsuhara ◽  
...  

2019 ◽  
Vol 490 (4) ◽  
pp. 5440-5450
Author(s):  
D A Prokhorov ◽  
A Moraghan

ABSTRACT One of the unsolved questions in γ-ray astronomy is whether the extragalactic γ-ray background is of the discrete-source origin. To respond to this question, one first needs to reduce the data by differentiating charged particles from γ-rays. This procedure is usually performed on the basis of the detector responses. In this paper, we showed that the geomagnetic shielding effect at GeV energies can, to some extent, be used for this purpose for γ-ray telescopes in a low Earth orbit. We illustrated this method by applying it to the Fermi Large Area Telescope data. To partially decompose the charge-filtered background, we examined the contribution from star-forming galaxies by implying a radio/γ-ray connection in consideration of next-generation radio surveys.


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