Related papers: The Post-Agb Star IRAS 16594-4656
We present 2 to 2.4 micron integral field spectroscopy of a sample of hot post-AGB stars with early-B spectral types, using the NIFS instrument on Gemini North. These stars are just beginning to ionize their immediate environments and turn…
We present a study of the high-resolution optical spectrum for the hot post-asymptotic giant branch (post-AGB) star, Hen 3-1013, identified as the optical counterpart of the infrared sourceIRAS 14331-6435. For the first time the detailed…
The transition from the Asymptotic Giant Branch (AGB) to the planetary nebula (PN) phase is critical in the shaping of PNe. It is suggested that the most asymmetric PNe are the descendant of massive AGB stars. Since these AGB stars are…
The chemical compositions of the C-rich pAGB stars IRAS 05113+1347 and IRAS 22272+5424 are determined from high-resolution optical spectra using standard LTE model atmosphere-based techniques. The stars are C, N, and $s$-process enriched…
We present high-angular resolution images of the post-AGB nebula IRAS18276-1431 (also known as OH17.7-2.0) obtained with the Keck II Adaptive Optics (AO) system in its Natural Guide Star (NGS) mode in the Kp, Lp, and Ms near-infrared bands.…
The high-resolution ($R\sim48\,000$) optical spectrum of the B-type supergiant LS 5112, identified as the optical counterpart of the post-AGB candidate IRAS 18379-1707, is analysed. We report the detailed identifications of the observed…
We performed an iron abundance determination of the hot, hydrogen deficient post-AGB star PG1159-035, which is the prototype of the PG1159 spectral class and the GW Vir pulsators, and of two related objects (PG1520+525, PG1144+005), based…
We present K-band integral field spectroscopy of the bipolar post-AGB object IRAS 18276-1431 (OH 17.7-2.0) using SINFONI on the VLT. This allows us to image both the continuum and molecular features in this object from 1.95-2.45{\mu}m with…
We present spectro-polarimetric observations of several molecular lines obtained with the Submillimeter Array (SMA) toward the carbon rich AGB star IRC+10216. We have detected and mapped the linear polarization of the CO 3-2, SiS 19-18 and…
We present here $Spitzer$ mid-infrared (IR) spectra and modeling of the spectral energy distribution (SED) of a selection of post-Asymptotic Giant Branch (PAGB) stars. The mid-IR spectra of majority of these sources showed spectral features…
Hot (OB) post-AGB stars are immediate progenitors of planetary nebulae (PNe). Very few hot post-AGB stars are known. Detecting new hot post-AGB candidates and follow-up multiwavelength studies will enable us to further understand the…
The narrow-line Seyfert 1 galaxy IRAS 07598+6508 is known to be a stong Fe II emitter. The analysis of several high S/N ratio spectra shows that its spectrum is dominated by a relatively narrow "broad line" region (1 780 km s$^{-1}$ FWHM)…
The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) is discovering a large number of new hard X-ray sources, many of them being HMXBs. The identification and spectral characterization of their optical/infrared counterparts is a…
We present the results of a spectroscopic analysis and spectral energy distribution (SED) modelling of the optical counterpart of the infrared source IRAS 22150+6109. The source was suggested to be as a Herbig Be star located in the star…
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen envelope, exposing the usually-hidden intershell…
An analysis of solid-state features in infrared spectra of 46 Herbig Ae/Be stars is presented. The presence of solid-state emission bands is compared to other indicators of circumstellar material, such as Halpha emission, optical…
Since its launch, the X-ray and gamma-ray observatory INTEGRAL satellite has revealed a new class of high-mass X-ray binaries (HMXB) displaying fast flares and hosting supergiant companion stars. Optical and infrared (OIR) observations in a…
We present the results of a near-infrared monitoring programme of a selected sample of stars, initially suspected to be Mira variables and OH/IR stars, covering more than a decade of observations. The objects monitored cover the typical…
We present near-IR spectroscopy of a sample of 30 IRAS sources recently identified as late AGB stars, post-AGB stars or early PNe. The spectra obtained are centered at various wavelengths covering the molecular hydrogen v=1-0 S(1) and v=2-1…
It is now well established that FGK post-AGB stars that are surrounded by both hot and cold dust (as derived from the spectral energy distribution), are almost always part of a binary system with $100 < P_{orb} < 5000$~days. The properties…