Related papers: K-band spectroscopy of pre-cataclysmic variables
Medium resolution (lambda/Delta lambda = 5000-10000) VLT-ISAAC M-band spectra are presented of 39 young stellar objects in nearby low-mass star forming clouds showing the 4.67 micron stretching vibration mode of solid CO. By taking…
Accretion discs are fundamental to much of astronomy. They can occur around stars both young and old, around compact objects they provide a window into the extremes of physics, and around supermassive black holes in galaxy centres they…
PDS 70c is a source of Ha emission and variable sub-mm signal. Understanding its emission mechanisms may enable observations of accretion rates and physical conditions in the circum-planetary environment. We report ALMA observations of PDS…
As deep spectroscopic campaigns extend to higher redshifts and lower stellar masses, the interpretation of galaxy spectra depends increasingly upon models for very young stellar populations. Here we present new HST/COS ultraviolet…
Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the presence of circumstellar gas in the…
We present an analytical study of a large sample of ~109 young stellar objects in the X-ray. Our objects were detected in X-ray independent of age. Unexpectedly, the X-ray energy is somewhat correlated with the ages. It decreases with time…
We present the first detection of the near-infrared CN absorption band in the nuclear spectra of active galactic nuclei (AGN). This feature is a recent star formation tracer, being particularly strong in carbon stars. The equivalent width…
The spatial distribution, galactic model parameters and luminosity function of cataclysmic variables (CVs) in the solar neighbourhood have been determined from a carefully established sample of 459 CVs. The sample contains all of the CVs…
The outer (>30 AU) regions of the dusty circumstellar disk orbiting the ~2-5 Myr-old, actively accreting solar analog LkCa 15 are known to be chemically rich, and the inner disk may host a young protoplanet within its central cavity. To…
We present spectroscopy and orbital periods Porb for 30 apparently non-magnetic cataclysmic binaries with periods below about 3 hours, nearly all of which are dwarf novae, mostly of the SU Ursae Majoris subclass. We then turn to the…
Our photometric monitoring revealed that DW Cnc, which was originally classified as a dwarf nova (V=15--17.5), remained at a bright state of Rc=14.68+/-0.07 for 61 days. In conjunction with optical spectra lacking a strong He II emission…
We discuss the properties of 137 cataclysmic variables (CVs) which are included in the Sloan Digital Sky Survey (SDSS) spectroscopic data base, and for which accurate orbital periods have been measured. 92 of these systems are new…
We present new H- and K-band spectroscopy for the bulge of M31, taken with the LUCI spectrograph at the Large Binocular Telescope (LBT). We studied radial trends of CO absorption features (namely, CO1.58, CO1.60, CO1.64, CO1.66, CO1.68,…
AM Canum Venaticorum (AM CVn) stars are ultra-compact binary systems composed of a white dwarf (WD) primary accreting from a H-deficient donor. They are important as potential progenitors of Type Ia supernovae and laboratories for…
We present K-band spectroscopy for several regions of three nearby spiral galaxies, NGC 613, NGC 628 and NGC 7741. Analysis of the depth of the 2.293 micron CO absorption feature in these spectra reveals that some regions have deep…
The "evolved main-sequence" channel is thought to contribute significantly to the population of AM CVn type systems in the Galaxy, and also to the number of cataclysmic variables detected below the period minimum for hydrogen rich systems.…
There are 15 cataclysmic variables (CVs) observed in the first two campaigns of the K2 mission. In this paper, the eight CVs showing distinct features are analyzed in detail. Among these eight, modulations during quiescence are evident at…
We critically re-examine the available data on the spectral types, masses and radii of the secondary stars in cataclysmic variables (CVs) and low-mass X-ray binaries (LMXBs), using the new catalogue of Ritter & Kolb (1998) as a starting…
We compare the X-ray spectra and luminosities, in the 2-8 keV band, of known and suspected cataclysmic variables (CVs) in different environments, assessing the nature of these source populations. These objects include nearby CVs observed…
We present the results of a program that monitored the near-IR spectroscopic variability of a sample of 19 embedded protostars. Spectra were taken on time intervals from 2 days to 3 years, over a wavelength range from 0.85 {\mu}m to 2.45…