Showing papers in "Revista Mexicana De Astronomia Y Astrofisica in 1985"

Near infrared photometry of violent star formation regions.

Abstract: On presente la photometrie dans l'IR proche et les indices CO pour un nombre significatif de regions de formation stellaire violente On confirme l'existence d'une etroite correlation entre W(Hβ) et la couleur IR

The spectrographic orbit of the eclipsing binary hh carinae

Abstract: We present a search for moving groups in the solar neighborhood. The search is done using the HIPPARCOS database and a new search method: the Spaghetti Metho...

On the planetary nebula NGC 3918.

Abstract: On a obtenu des spectres IUE de haute dispersion pour NGC 3918 On a mesure et analyse les intensites des raies d'emission La nebuleuse ne presente pas de variations de densite systematiques On a obtenu les abondances ioniques et une valeur pour le defaut d'abondance du magnesium dans la composante gazeuse des regions externes de la nebuleuse On a mesure la vitesse d'expansion pour divers ions: on trouve qu'elle croit lorsque le degre d'ionisation diminue Le champ des vitesses comparable avec une expansion isotherme dans le vide On a evalue l'âge cinematique a ∼3100 ans

Explosions during galaxy formation

Abstract: RESUMEN El resumen sera traducido al espanol por los editores. As an idealized model of the effects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of filaments in the plane of a cosmological pancake by gravitational in- stability during pancake collapse. Such halos resemble the virialized objects found in N-body simulations in a CDM universe and, therefore, serve as a convenient, scale-free test-bed model for galaxy formation. ASPH/P 3 M simulations reveal that such explosions are anisotropic. The energy and metals are channeled into the low density regions, away from the pancake plane. The pancake remains essen- tially undisturbed, even if the explosion is strong enough to blow away all the gas located inside the halo at the onset of the explosion and reheat the IGM surround- ing the pancake. Infall quickly replenishes this ejected gas and gradually restores the gas fraction as the halo mass continues to grow. Estimates of the collapse epoch and SN energy-release for galaxies of different mass in the CDM model can relate these results to scale-dependent questions of blow-out and blow-away and their implication for early IGM heating and metal enrichment and the creation of dark-matter-dominated dwarf galaxies. ABSTRACT As an idealized model of the effects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of filaments in the plane of a cosmological pancake by grav- itational instability during pancake collapse. Such halos resemble the virialized objects found in N-body simulations in a CDM universe and, therefore, serve as a convenient, scale-free test-bed model for galaxy formation. ASPH/P 3 M simulations reveal that such explosions are anisotropic. The energy and metals are channeled into the low density regions, away from the pancake plane. The pancake remains essentially undisturbed, even if the explosion is strong enough to blow away all the gas located inside the halo at the onset of the explosion and reheat the IGM surrounding the pancake. Infall quickly replenishes this ejected gas and gradually restores the gas fraction as the halo mass continues to grow. Estimates of the col- lapse epoch and SN energy-release for galaxies of different mass in the CDM model can relate these results to scale-dependent questions of blow-out and blow-away and their implication for early IGM heating and metal enrichment and the creation of dark-matter-dominated dwarf galaxies.

Light maxima of the delta Scuti star HD 94033.

Abstract: Earlier studies about asteroids did not consider mutual interactions since they assume a negligible asteroid mass In 1966 Hertz took into account for the fi

Thirteen - color photometry, san pedro martir. Part ii. 1980 - 1983

Abstract: On donne les donnees d'extinction atmospherique, les coefficients de couleur et les residuels de transformation pour 98 nuits de photometrie 13 couleurs

Research note: absolute UBV photometry at the Zacatecas observatory

Abstract: On donne les coefficients de couleurs, les donnees d'extinction atmospherique, les erreurs d'observation et une liste d'etoiles standard et de comparaison pour une photometrie UBV a l'observatoire de Zacatecas

The WN4+O8V spectroscopic binary HD 94546.

Abstract: On presente de nouvelles observations du systeme binaire spectroscopique HD 94546 et on determine ses parametres orbitaux. HD 94546 est composee d'une etoile WN4 et d'une etoile O8V

Stellar populations in galaxies: Progress on the milky way, on dwarf irregulars, and on elliptical galaxies

Abstract: On propose une evaluation de la contribution des novae, des etoiles de masse intermediaire et des etoiles massives a l'enrichissement en 12 C et 13 C du milieu interstellaire

H-alpha profile variations in variable luminous yellow supergiants.

Abstract: Profils des raies Hα dans les supergeantes jaunes lumineuses variables HD 161796, 89 Her, E Aur, V509 Cas et ρ Cas. On detecte des variations dans les profils sur des echelles de temps de mois et de semaines, et on discute de la nature de ces profils