相关论文: Ionizing Photon Emission Rates from O- and Early B…

The shape of the OB-star spectral energy distribution is a critical component in many diagnostics of the ISM and galaxy properties. We use single-star HII regions from the LMC to quantitatively examine the ionizing SEDs from widely…

We compute the production rate of photons in the ionizing Lyman continua (LyC) of H I (lambda < 912 A), He I (lambda < 504 A), and He II (lambda < 228 A) using recent stellar evolutionary tracks coupled to a grid of non-LTE, line-blanketed…

We provide an extensive set of theoretical spectral energy distributions of massive stars derived from our "combined stellar structure and atmosphere models". The calculations covering the entire main sequence evolution for initial masses…

We present a systematic study of the effect of metallicity on the stellar spectral energy distribution (SED) of O main sequence (dwarf) stars, focussing on the hydrogen and helium ionizing continua, and on the optical and near-IR lines used…

Medium-resolution spectra from 3650 angstroms to 10,000 angstroms are presented for 96 giant H II regions distributed in 20 spiral galaxies. We have calculated two separate grids of photoionization models, adopting single-star atmospheres…

We present a detailed comparison of the ionizing spectral energy distributions (SEDs) predicted by four modern stellar atmosphere codes, TLUSTY, CMFGEN, WMbasic, and FASTWIND. We consider three sets of stellar parameters representing a late…

Wind models of very massive stars with metallicities in a range from 1E-4 to 1.0 solar are calculated using a new treatment of radiation driven winds with depth dependent radiative force multipliers and a comprehensive list of more than two…

We calculate the generic spectral signature of an early population of massive stars at high redshifts. For metal-free stars in the mass range of 100-1000 solar masses, we find that the combined spectral luminosity per unit stellar mass is…

This is the second paper of a series reporting the results from the PopStar evolutionary synthesis models. Here we present synthetic emission line spectra of H{\sc ii} regions photoionized by young star clusters, for seven values of cluster…

In order to better determine the physical properties of hot, massive stars as a function of metallicity, we obtained very high SNR optical spectra of 26 O and early B stars in the Magellanic Clouds. These allow accurate modeling even in…

Context. Late O-type stars at luminosities $\log L/L_\odot \lesssim 5.2$ show weak winds with mass-loss rates lower than 10$^{-8} M_\odot$ yr$^{-1}$. This implies that their photospheric layers are not strongly affected by the stellar wind.…

Spectral Energy Distribution (SED) fitting is a well-developed astrophysical tool that has recently been applied to high-redshift Lyman Alpha-emitting galaxies. If rest-frame ultraviolet through near-infrared photometry is available, it…

The 20 cm radio continuum fluxes of 91 HII regions in a previously compiled catalog have been determined. The spectral types of the ionizing stars in 42 regions with known distances are estimated. These spectral types range from B0.5 to O7,…

We have obtained HST and ground-based observations of a sample of 20 O-type stars in the LMC and SMC, including six of the hottest massive stars known (subtypes O2-3) in the R136 cluster. In general, these data include (a) the HST UV…

We calculate models of extended stellar atmospheres with a temperature in the range of 12000-40000K and a mass loss rate of $10^{-6}-10^{-4} M_{\odot}$ yr$^{-1}$. A large number of objects with emission spectra, such as luminous blue…

Photoionizing radiation and stellar winds from massive stars deposit energy and momentum into the interstellar medium (ISM). They might disperse the local ISM, change its turbulent multi-phase structure, and even regulate star formation.…

Star-forming galaxies with nebular HeII emission contain very energetic ionizing sources of radiation, which can be considered as analogs to the major contributors of the reionization of the Universe in early epochs. It is therefore of…

The spectral energy distribution (SED) of recent star formation regions is dominated by the more massive and early stars (O and B types). These stars show large and very significant absorption features, the most prominent being the…

We study the production rate of ionizing photons of a sample of 588 H$\alpha$ emitters (HAEs) and 160 Lyman-$\alpha$ emitters (LAEs) at $z=2.2$ in the COSMOS field in order to assess the implied emissivity from galaxies, based on their UV…

We present mid-IR photometric properties for a sample of 28 early-type galaxies observed at 6.75, 9.63 and 15 um with the ISOCAM instrument on board the ISO satellite. We find total mid-IR luminosities in the range 3-48x10^8 L_sun. The…