Skip to main content

8 Result(s)

within N. Panagia Remove this filter Space Sciences (including Extraterrestrial Physics, Space Exploration and Astronautics) Remove this filter

and

  1. No Access

    Article

    On the spectrum of a gaseous nebula of pure hydrogen, I

    The emissivity for the two photons decay from the metastable level 2s has been computed in the case of a gaseous nebula of pure hydrogen, with both radiative and collisional excitation of the states.

    H. Gerola, N. Panagia in Astrophysics and Space Science (1968)

  2. No Access

    Article

    On the spectrum of a gaseous nebula of pure hydrogen, II

    Calculations of the optical continuum of a nebula of pure hydrogen were carried out, taking into account, together, with the recombination emission, the two-photon emission and the continuous emission in the r...

    H. Gerola, N. Panagia in Astrophysics and Space Science (1970)

  3. No Access

    Article

    On the spectrum of a gaseous nebula of pure hydrogen

    The Balmer decrement was calculated for a homogeneous, spherical, pure hydrogen nebula, ionised and excited both by radiative and collisional processes. Reabsorption in the Balmer series from sublevels 2s and 2p ...

    H. Gerola, M. Salem, N. Panagia in Astrophysics and Space Science (1971)

  4. No Access

    Article

    Self-accretion of matter, red subluminous stars and early evolution of low-mass stars

    Low-mass stars during their pre-main sequence contraction phase are expected to be surrounded by a certain amount of the primordial gas. At low luminosities, accretion of this gas can make the stars to follow ...

    V. Castellani, N. Panagia in Astrophysics and Space Science (1972)

  5. No Access

    Article

    A study of M100 in X-rays

    During a search for X-ray emission from Supernova 1979c, the parent galaxy M100 (NGC 4321) was repeatedly observed with the IPC and HRI instruments aboard the Einstein X-ray Observatory. The X-ray data reveal ...

    G. G. C. Palumbo, T. Maccacaro, N. Panagia, G. Vettolani… in Space Science Reviews (1981)

  6. No Access

    Article

    Hydrogen and helium ionization structure of gaseous nebulae

    In this paper we discuss the ionization equilibrium of hydrogen and helium in a nebula with an arbitrary gas density distribution.

    E. Oliva, N. Panagia in Astrophysics and Space Science (1983)

  7. No Access

    Article

    Five supernova survey galaxies in the southern hemisphere. I. Optical and near-infrared database

    The determination of the supernova (SN) rate is based not only on the number of detected events, but also on the properties of the parent galaxy population. This is the first paper of a series aimed at obtaini...

    A. A. Hakobyan, A. R. Petrosian, G. A. Mamon, B. McLean, D. Kunth… in Astrophysics (2009)

  8. No Access

    Article

    Five supernova survey galaxies in the southern hemisphere. II. the supernova rates

    Based on the database compiled in the first article of this series, with 56 SN events discovered in 3838 galaxies of the southern hemisphere, we compute the rate of supernovae (SNe) of different types along th...

    A. A. Hakobyan, A. R. Petrosian, G. A. Mamon, B. McLean, D. Kunth… in Astrophysics (2011)