Bibcode
Henry, R. B. C.; Balick, B.; Dufour, R. J.; Kwitter, K. B.; Shaw, R. A.; Miller, T. R.; Buell, J. F.; Corradi, R. L. M.
Referencia bibliográfica
The Astrophysical Journal, Volume 813, Issue 2, article id. 121, 19 pp. (2015).
Fecha de publicación:
11
2015
Revista
Número de citas
14
Número de citas referidas
13
Descripción
The goal of the present study is twofold. First, we employ new HST/STIS
spectra and photoionization modeling techniques to determine the
progenitor masses of eight planetary nebulae (IC 2165, IC 3568, NGC
2440, NGC 3242, NGC 5315, NGC 5882, NGC 7662, and PB 6). Second, for the
first time we are able to compare each object’s observed nebular
abundances of helium, carbon, and nitrogen with abundance predictions of
these same elements by a stellar model that is consistent with each
object’s progenitor mass. Important results include the following:
(1) the mass range of our objects’ central stars matches well with
the mass distribution of other central stars of planetary nebulae and
white dwarfs; (2) He/H is above solar in all of our objects, in most
cases likely due to the predicted effects of first dredge-up; (3) most
of our objects show negligible C enrichment, probably because their low
masses preclude third dredge-up; (4) C/O versus O/H for our objects
appears to be inversely correlated, which is perhaps consistent with the
conclusion of theorists that the extent of atmospheric carbon enrichment
from first dredge-up is sensitive to a parameter whose value increases
as metallicity declines; (5) stellar model predictions of nebular C and
N enrichment are consistent with observed abundances for progenitor star
masses ≤1.5 M⊙. Finally, we present the first
published photoionization models of NGC 5315 and NGC 5882.
Based on observations with the NASA/ESA Hubble Space Telescope obtained
at the Space Telescope Science Institute, which is operated by the
Association of Universities for Research in Astronomy, Incorporated,
under NASA contract NAS5-26555.
Proyectos relacionados
Nebulosas Bipolares
Nuestro proyecto persigue tres objetivos principales: 1) Determinar las condiciones físico-químicas de las nebulosas planetarias con geometría bipolar y de las nebulosas alrededor de estrellas simbióticas. El fin es entender el origen de la bipolaridad y poner a prueba los modelos teóricos que intentan explicar la morfología y la cinemática nebular
Antonio
Mampaso Recio