Search Publications
Variability of the emission line fluxes and ratios of HH 1/2
Raga, A. C.; Reipurth, B.; Castellanos-Ramírez, Bally, J.
We compare spectrophotometric data of HH 1 and 2 obtained in 1978 (by Brugel et al. 1981a) with the emission line fluxes from calibrated Hubble Space Telescope (HST) images obtained in 1994 and 2014. This comparison shows that the emission line ratios of these objects have remained surprisingly invariant during the past 36 years. On the other hand…
Chemical Abundances and Physical Parameters of HII Regions in the Magellanic Clouds
Meléndez, J.; Steiner, J.; Carlos Reyes, R. E. +2 more
We used ultraviolet, optical and infrared data of eleven HII regions in the Magellanic Clouds in order to determine their physical parameters and chemical abundances. The photoionization modeling of six HII regions in the LMC and five HII regions in the SMC, allowed us to derive the abundances of He, C, N, O, Ne, S and Ar, which were compared with…
Spectroscopic analysis of four post-AGB candidates
Pereira, C. B.; Arellano Ferro, A.; Muneer, S. +2 more
We have done a detailed abundance analysis of four unexplored candidate post- Asymptotic Giant Branch(AGB) stars IRAS 13110 - 6629, IRAS 17579 - 3121, IRAS 18321 - 1401 and IRAS 18489 - 0629 using high resolution spectra. We have constructed Spectral Energy Distributions (SED) for these objects using the existing photometric data combined with inf…
Radio Continuum Sources associated with the HH 92 and HH 34 Jets
Rodríguez, Luis F.; Reipurth, Bo; Chiang, Hsin-Fang
We present high angular resolution, high sensitivity 8.46 GHz (3.6 cm) radio continuum observations made toward the core of the HH 92 outflow with the Very Large Array in 2002-2003 and with the Expanded Very Large Array in 2011. We detect a group of three compact sources distributed in a region 2'' in extension and discuss their nature. We conclud…
A one-sided knot ejection at the core of the HH 111 outflow
Loinard, L.; Rodríguez, L. F.; Gómez, L.
We present an astrometry study of the radio source VLA 1 at the core of the HH 111 outflow using new data (2007) as well as archival observations (1992-1996). All data were taken at 3.6 cm with the Very Large Array in its most extended (A) configuration. The source VLA 1 has undergone a dramatic morphological change, showing a one-sided knot eject…
Radio Sources Embedded in the Dense Core B59, the ``Mouthpiece'' of the Pipe Nebula
Loinard, L.; Rodríguez, L. F.; Dzib, S. A. +1 more
We present Very Large Array continuum observations made at 8.3 GHz toward the dense core B59, in the Pipe Nebula. We detect six compact sources, of which five are associated with the five most luminous sources at 70 µm in the region, while the remaining one is probably a background source. We propose that the radio emission is free-free from…
Optical Spectroscopic Atlas of the MOJAVE/2cm AGN Sample
Chavushyan, V.; Rosa-González, D.; Torrealba, J. +3 more
We present an optical spectroscopic atlas for 123 core-dominated radio-loud active galactic nuclei with relativistic jets, drawn from the MOJAVE/2cm sample at 15 GHz. It is the first time that spectroscopic and photometric parameters for a large sample of such type of AGN are presented. The atlas includes spectral parameters for the emission lines…
Mid- and Far-Infrared Photometry of Galactic Planetary Nebulae with the AKARI All-Sky Survey
Phillips, J. P.; Márquez-Lugo, R. A.
We provide mid- and far-infrared photometry of 857 Galactic planetary nebulae (PNe) using data derived from the AKARI All-Sky Survey. These include fluxes at 9 and 18 µm obtained with the Infrared Camera (IRC), and at 65, 90, 140 and 160 µm using the far-Infrared Surveyor (FIS). It is noted that the IR luminosities of the youngest PNe …
Variable jets with non-top hat ejection cross sections: a model for the knots of the HH 34 jet
Raga, A. C.; Noriega-Crespo, A.; Esquivel, A. +3 more
We compute axisymmetric, single-sinusoidal mode variable ejection models with a non-top hat ejection velocity cross section. We find that for decreasing edge-to-center velocity ratios one obtains internal working surfaces with progressively more extended bow shock wings. These wings produce [S II] emission which partially fills in the inter-knot r…
The Kinematics and Velocity Ellipsoid of the G III Stars
Branham, R. L., Jr.
To study the kinematics of the G giant stars (luminosity class III) use is made of proper motions and parallaxes taken from van Leeuwen's new reduction of the Hipparcos catalog. 3,075 stars, of which 658 have radial velocities, were used in the final study. The solution gives: solar velocity of 16.72±0.41 km s-1; Oort's constant's, in u…