Search Publications
Pre-nova X-ray observations of V2491 Cygni (Nova Cyg 2008b)
Mukai, K.; Hernanz, M.; Sala, G. +12 more
Classical novae are phenomena caused by explosive hydrogen burning onto an accreting white dwarf. Only one classical nova had been identified in X-rays before the actual optical outburst occurred (V2487 Oph). The recently discovered nova, V2491 Cyg, is one of the fastest (He/N) novae observed to date. Using archival ROSAT, XMM-Newton, and Swift da…
Spectral and temporal variations of the isolated neutron star RX J0720.4-3125: new XMM-Newton observations
Haberl, F.; de Vries, C. P.; Vink, J. +5 more
Context: In the past, the isolated, radio-quiet neutron star RX J0720.4-3125 showed variations in its spectral parameters (apparent radius, temperature of the emitting area and equivalent width of the absorption feature) seen in the X-ray spectra, not only during the spin period of 8.39 s, but also over time scales of years. New X-ray observations…
Results from DROXO. II. [Ne II] and X-ray emission from ρ Ophiuchi young stellar objects
Testi, L.; Micela, G.; Sciortino, S. +3 more
Context: The infrared [Ne II] and [Ne III] fine structure lines at 12.81 µm and 15.55 µm have recently been theoretically predicted to trace the circumstellar disk gas subject to X-ray heating and ionization.
Aims: We observationally investigate the origin of the neon fine structure line emission by comparing observations with mode…
Circumstellar water vapour in M-type AGB stars: constraints from H{2}O(1{10}-1{01}) lines obtained with Odin
Olofsson, H.; Justtanont, K.; Larsson, B. +8 more
Context: A detailed radiative transfer code has been previously used to model circumstellar ortho-{H_2O} line emission towards six M-type asymptotic giant branch stars using Infrared Space Observatory Long Wavelength Spectrometer data. Collisional and radiative excitation, including the {ν_2=1} state, was considered.
Aims: Spectrally resolved …
A spatial study of the mid-IR emission features in four Herbig Ae/Be stars
Waters, L. B. F. M.; Tielens, A. G. G. M.; Boersma, C. +5 more
Context: Infrared (IR) spectroscopy and imaging provide a prime tool to study the characteristics of polycyclic aromatic hydrocarbon (PAH) molecules and the mineralogy in regions of star formation. Herbig Ae/Be stars are known to have varying amounts of natal cloud material present in their vicinity.
Aims: Our aim is to study the characteristi…
The flared inner disk of the Herbig Ae star AB Aurigae revealed by VLTI/MIDI in the N-band
Wolf, S.; Lopez, B.; Leinert, Ch. +4 more
Aims: We aim at using the long baselines of the VLT Interferometer and the mid-IR combiner MIDI (8-13 µm) to derive the morphology of the protoplanetary disk surrounding the Herbig Ae star AB Aurigae
Methods: We present the first N-band analysis of AB Aur performed with a maximum angular resolution of 17 mas (2.5 AU at the Taurus-Auriga …
Long tails on thermonuclear X-ray bursts from neutron stars: a signature of inward heating?
Homan, J.; in't Zand, J. J. M.; Méndez, M. +3 more
We report the discovery of one-hour long tails on the few-minutes long X-ray bursts from the “clocked burster” GS 1826-24. We propose that the tails are due to enduring thermal radiation from the neutron star envelope. The enduring emission can be explained by cooling of deeper neutron star layers that were heated up through inward conduction of h…
Detection of X-rays from the jet-driving symbiotic star MWC 560
Stute, M.; Sahai, R.
Aims: We report the detection of X-ray emission from the jet-driving symbiotic star MWC 560.
Methods: We observed MWC 560 with XMM-Newton for 36 ks. We fitted the spectra from the EPIC pn, MOS1 and MOS2 instruments with XSPEC and examined the light curves with the package XRONOS.
Results: The spectrum can be fitted with a highly absorbed h…
Modeling the X-ray emission of SN 1993J
Fransson, C.; Nymark, T. K.; Chandra, P.
Aims: We investigate the effects of radiative shocks on the observed X-ray emission from the type II supernova SN 1993J. To this end, the X-ray emission is modeled as a result of the interaction between the supernova ejecta and a dense circumstellar medium at an age of 8 years.
Methods: The circumstances under which the reverse shock is radiat…
The role of environment in the morphological transformation of galaxies in 9 rich intermediate redshift clusters
Pelló, R.; Huertas-Company, M.; Soucail, G. +1 more
Context: Rich clusters offer a unique laboratory for studying the effects of local environment on the morphological transformation of galaxies moving from the blue star-forming cloud to the red passive sequence. Due to the high-density, any environmental process should be more pronounced there compared to the field population.
Aims: Ideally, w…