ISM properties in low-metallicity environments
نویسندگان
چکیده
منابع مشابه
Thermal and Fragmentation Properties of Star-forming Clouds in Low-metallicity Environments
The thermal and chemical evolution of star-forming clouds is studied for different gas metallicities, Z, using the model of Omukai (2000), updated to include deuterium chemistry and the effects of cosmic microwave background (CMB) radiation. HD-line cooling dominates the thermal balance of clouds when Z ∼ 10−5 − 10Z⊙ and density ≈ 105cm−3. Early on, CMB radiation prevents the gas temperature to...
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Massive B-type pulsators such as β Cep and slowly pulsating B (SPB) stars pulsate due to layers of increased opacity caused by partial ionization. The increased opacity blocks the energy flux to the surface of the stars which causes the layers to rise and the opacity to drop. This cyclical behavior makes the star act as a heat engine and the star will thus pulsate. For β Cep and SPB stars the i...
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Aims. Massive stars in low-metallicity environments may produce exotic explosions such as long-duration gamma-ray bursts and pair-instability supernovae when they die as core-collapse supernovae (CCSNe). Such events are predicted to be relatively common in the early Universe during the first episodes of star-formation. To understand these distant explosions it is vital to study nearby CCSNe ari...
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We review the available estimates of the masses of the compact object in Ultraluminous X-ray Sources (ULXs) and critically reconsider the stellar-mass versus intermediatemass black hole interpretations. Black holes of several hundreds to thousands of M are not required for the majority of ULXs, although they might be present in the handful of known hyper-luminous (∼ 10 erg s−1) objects and/or s...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2005
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20042369