Zobrazeno 1 - 10
of 58
pro vyhledávání: '"Schwarz, Hugo E."'
Autor:
Krisciunas, Kevin, Semler, Dylan R., Richards, Joseph, Schwarz, Hugo E., Suntzeff, Nicholas B., Vera, Sergio, Sanhueza, Pedro
We present optical UBVRI sky brightness measures from 1992 through 2006. The data are based on CCD imagery obtained with the CTIO 0.9-m, 1.3-m, and 1.5-m telescopes. The B- and V-band data are in reasonable agreement with measurements previously made
Externí odkaz:
http://arxiv.org/abs/0705.1153
We show that the inclination to the line of sight of bipolar nebulae strongly affects some of their observed properties. We model these objects as having a spherically symmetric Planetary Nebula and a dusty equatorial density enhancement that produce
Externí odkaz:
http://arxiv.org/abs/astro-ph/0609467
Autor:
Schwarz, Hugo E., Monteiro, Hektor
Publikováno v:
Astrophys.J.648:430-434,2006
Continuing our series of papers on the three-dimensional (3-D) structures of and accurate distances to Planetary Nebulae (PNe), we present our study of the planetary nebula NGC6781. For this object we construct a 3-D photoionization model and, using
Externí odkaz:
http://arxiv.org/abs/astro-ph/0604501
Autor:
Monteiro, Hektor, Schwarz, Hugo E., Gruenwald, Ruth, Guenthner, Katherine, Heathcote, Steve R.
Publikováno v:
Astrophys.J. 620 (2005) 321-329
We present the results of a spatio-kinematic study of the planetary nebula Menzel 1 using spectro-photometric mapping and a 3-D photoionization code. We create several 2-D emission line images from our long-slit spectra, and use these to derive the l
Externí odkaz:
http://arxiv.org/abs/astro-ph/0410496
Publikováno v:
Astrophys.J. 609 (2004) 194-202
We present the results of mapping the planetary nebula NGC6369 using multiple long slit spectra taken with the CTIO 1.5m telescope. We create two dimensional emission line images from our spectra, and use these to derive fluxes for 17 lines, the Halp
Externí odkaz:
http://arxiv.org/abs/astro-ph/0403355
Publikováno v:
Astron.Astrophys. 417 (2004) 637-646
We present a search for rings or arcs in the haloes of planetary nebulae (PNe). We discovered such structures in eight PNe, tripling the sample of PNe with known rings. This shows that, contrary to what was believed to date, the occurrence of mass lo
Externí odkaz:
http://arxiv.org/abs/astro-ph/0401056
Publikováno v:
Astrophys.J.603:595-598,2004
We have measured the proper motion (PM) and kinematics of the ansae in NGC 7009 using high dispersion echelle spectra and archive narrow band HST images. Assuming that the ansae are moving at equal and opposite velocities from the central star we obt
Externí odkaz:
http://arxiv.org/abs/astro-ph/0311612
Autor:
Schwarz, Hugo E., Monteiro, Hektor
We show that there are strong links between certain types of asymmetrical Planetary Nebulae (PNe) and symbiotic stars. Symbiotics are binaries and several have extended optical nebulae all of which are asymmetrical and ~-40% are bipolar. Bipolar PNe
Externí odkaz:
http://arxiv.org/abs/astro-ph/0310074
In this work we investigate how a circumstellar disk affects the radiation emitted by an embedded star. We show correlations obtained from broad-band observations of bipolar nebulae indicating that an orientation effect is at play in these systems. T
Externí odkaz:
http://arxiv.org/abs/astro-ph/0310075