منابع مشابه
The Compact Uv Nucleus of M 33
The most luminous X-ray source in the Local Group is associated with the nucleus of M33. This source, M33 X-8, appears modulated by ∼ 20% over a ∼ 106 day period, making it unlikely that the combined emission from unresolved sources could explain the otherwise persistent ∼10erg s X-ray flux (Dubus et al. 1997, Hernquist et al. 1991). We present here high resolution UV imaging of the nucleus wit...
متن کاملThe Dusty Starburst Nucleus of M33
We have thoroughly characterized the ultraviolet to near-infrared (0.15 2.2 μm) spectral energy distribution (SED) of the central parsec of the M33 nucleus through new infrared photometry and optical/near-infrared spectroscopy, combined with ultraviolet/optical observations from the literature and the HST archive. The SED shows evidence for a significant level of attenuation, which we model thr...
متن کاملAn analysis of STIS HST UV spectra of M33 early B supergiants
We present terminal velocities of M33 B-supergiants, obtained from STIS HST spectra as part of our programme to investigate the Wind Momentum – Luminosity Relationship (WLR) in the Local Group. Terminal velocities are derived from their N V, C IV, and Si IV resonance lines in UV spectra. Comparing with IUE spectra of Galactic B-supergiants we found evidence of low metallicity in three of our ob...
متن کاملThe M33 Metallicity Project: Resolving the Abundance Gradient Discrepancies in M33
We present a new determination of the metallicity gradient in M33, based on Keck LRIS measurements of oxygen abundances using the temperature-sensitive emission line [O iii] k4363 in 61 H ii regions. These data approximately triple the sample of direct oxygen abundances in M33. We find a central abundance of 12þ log (O/H) 1⁄4 8:36 0:04 and a slope of 0:027 0:012 dex kpc , in agreement with infr...
متن کاملthe effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 1999
ISSN: 0004-637X
DOI: 10.1086/312113