Related papers: High-energy emission from star-forming galaxies
Air shower experiments have detected cosmic ray events of energies upto 300 EeV. Most likely these cosmic rays have originated from compact objects. Their exact sources are yet to be identified. It has been suggested before that gamma ray…
The interstellar medium of galaxies, with temperatures reaching several million degrees, provides a pivotal perspective for understanding the physical and chemical properties of star formation, galactic evolution, and their associated…
The star formation (SF) can be regarded as an engine powering the light emission of spiral galaxies at several wavelengths. SF activity also plays a significant role in the evolution of galaxies. In this thesis we focus on the X-ray…
Reanalysis of Einstein IPC data and new observations from the GINGA LAC indicate the presence of extended X-ray emission (10-50 kpc) around the starburst galaxy M82. Here we model this emission by calculating numerical hydrodynamic…
Integrated X-ray spectra of an evolving population of starburst galaxies (SBGs) are determined based on the observed spectra of local SBGs. In addition to emission from hot gas and binary systems, our model SBG spectrum includes a…
A point-like source of ~TeV gamma-rays has recently been seen towards the Galactic center by HESS and other air Cerenkov telescopes. In recent work (Ballantyne et al. 2007), we demonstrated that these gamma-rays can be attributed to…
Particle acceleration in the inner ~ 200 pc of the Galaxy is discussed, where diffuse TeV gamma-rays have been detected by the High Energy Stereoscopic System (HESS) observation. The diffuse gamma-ray emission has a strong correlation with…
We select 947 star-forming galaxies from SDSS-DR7 with [O~{\sc iii}]$\lambda$4363 emission lines detected at a signal-to-noise {ratio }larger than 5$\sigma$. Their electron temperatures and direct oxygen abundances are {then }determined.…
Gamma ray observations have found evidence of an extremely energetic outflow emanating from the Galactic Centre, and an `excess' of emission at GeV energies towards the Galactic Centre over that expected from current models. Determining…
Cosmic rays travel throughout the Galaxy, leaving traces from radio to ultra-high-energy gamma rays due to interactions with the interstellar gas, radiation field and magnetic field. Therefore, it is necessary to utilize multi-wavelength…
We present a new phenomenological model for the spectral energy distribution of normal star-forming galaxies between 3 and 1100 microns. A sequence of realistic galaxy spectra are constructed from a family of dust emission curves assuming a…
Recent optical surveys have identified a rare population of low-$z$ ($z \sim 0.01 - 0.06$) extreme star-forming galaxies (xSFGs) characterized by very low metallicity, strong emission lines, extremely high specific star-formation rate, low…
The radio continuum spectra of 14 star-forming galaxies are investigated by fitting nonthermal (synchrotron) and thermal (free-free) radiation laws. The underlying radio continuum measurements cover a frequency range of ~325 MHz to 24.5 GHz…
The galaxies M82, NGC 253, NGC 1068, and NGC 4945 have been detected in gamma-rays by Fermi. Previously, we developed and tested a model for cosmic ray interactions in the starburst galaxy M82. Now, we aim to explore the differences between…
About 10 candidate Halpha emitting galaxies at z = 2.2 have been detected in a 2.1 um narrow band imaging survey covering an area of 100 sq. arcmin including the WFPC2 and STIS fields in the Hubble Deep Field South. Six of these have…
Recent detections of the starburst galaxies M82 and NGC 253 by gamma-ray telescopes suggest that galaxies rapidly forming massive stars are more luminous at gamma-ray energies compared to their quiescent relatives. Building upon those…
The analytic galactic wind model derived by Chevalier and Clegg in 1985 (CC85) assumes $\textit{uniform}$ energy and mass-injection within the starburst galaxy nucleus. However, the structure of nuclear star clusters, bulges, and…
In this paper we present a three-dimensional numerical model for the radio emission of Magnetic Chemically Peculiar stars, on the hypothesis that energetic electrons emit by the gyrosynchrotron mechanism. For this class of radio stars,…
Star-forming and starburst galaxies, which are well-known cosmic-rays reservoirs, are expected to emit gamma-rays and neutrinos predominantly via hadronic collisions. In this Letter, we analyze the 10-year Fermi-LAT spectral energy…
Starburst galaxies are well-motivated astrophysical emitters of high-energy gamma-rays. They are well-known cosmic-ray "reservoirs", thanks to their large magnetic fields which confine high-energy protons for $\sim 10^5$ years. Over such…