Search Publications
Pair lines of sight observations of multiphase gas bearing O VI in a galaxy environment
Beckett, Alexander; Morris, Simon L.; Muzahid, Sowgat +2 more
Using HST/COS spectra of the twin quasar lines of sight Q 0107-025A & Q 0107-025B, we report on the physical properties, chemical abundances, and transverse sizes of a multiphase medium in a galaxy field at z = 0.399. The angular separation between the quasars corresponds to a physical separation of 520 kpc at the absorber redshift. The absorb…
Stereoscopic measurements of coronal Doppler velocities
Barczynski, K.; Mierla, M.; Berghmans, D. +8 more
Context. The Solar Orbiter mission, with an orbit outside the Sun-Earth line and leaving the ecliptic plane, opens up opportunities for the combined analysis of measurements obtained by solar imagers and spectrometers. For the first time different space spectrometers will be located at wide angles to each other, allowing three-dimensional (3D) spe…
GTC/CanariCam Deep Mid-infrared Imaging Survey of Northern Stars within 5 pc
Rebolo, Rafael; Caballero, José A.; Pinfield, David J. +7 more
In this work we present the results of a direct imaging survey for brown dwarf companions around the nearest stars at the mid-infrared 10 micron range (λ c = 8.7 µm, Δλ = 1.1 µm) using the CanariCam instrument on the 10.4 m Gran Telescopio Canarias (GTC). We imaged the 25 nearest stellar systems within 5 pc of the Sun at d…
An XMM-Newton catalogue of BL Lacs
Racero, E.; Álvarez Crespo, N.; de la Calle Pérez, I. +1 more
Aims: We present an XMM-Newton catalogue of BL Lac X-ray, optical, and UV properties based on cross-correlation with the 1151 BL Lacs listed in the fifth edition of the Roma-BZCAT.
Methods: We searched for the X-ray counterparts to these objects in the field of view of all pointed observations in the XMM-Newton archive over nearly 20 yea…
Blueshifted Hydrogen Emission and Shock Wave of RR Lyrae Variables in SDSS and LAMOST
Deng, Licai; Liu, Chao; Zhang, Huawei +4 more
Hydrogen emissions of RR Lyrae variables are the imprints of shock waves traveling through their atmospheres. We develop a pattern recognition algorithm, which is then applied to single-epoch spectra of the Sloan Digital Sky Survey and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope survey. These two spectroscopic surveys covered ~10…
Spectral study of V565 Mon: probable FU Ori-like or chemically peculiar star
Andreasyan, Hasmik
We present a detailed spectroscopic study of pre-main sequence star V565 Mon, which is the illuminating star of the Parsamian 17 cometary nebula. Observations were performed with the 2.6 m telescope in Byurakan Astrophysical Observatory on 2018 February 15. Radial velocities and equivalent widths of the most prominent lines of V565 Mon are present…
The local vertical density distribution of ultracool dwarfs M7 to L2.5 and their luminosity function
Warren, Stephen J.; Ahmed, Saad; Laithwaite, Richard C.
We investigate the form of the local vertical density profile of the stars in the Galactic disk, close to the Galactic plane. We use a homogeneous sample of 34000 ultracool dwarfs M7 to L2.5 that all lie within 350 pc of the plane. We fit a profile of the form sech$^\alpha$, where $\alpha=2$ is the theoretically preferred isothermal profile and $\…
Spectroscopic and photometric analysis of the eclipsing binary HIP 7666 with δ Scuti pulsations
Esamdin, Ali; Wang, Liang; Cang, Tianqi +14 more
New multicolour photometric observations were carried out on 22 nights in three observation missions between 2015 October and 2016 February for eclipsing binary HIP 7666. High- and low-resolution spectroscopic observations were also carried out in the winters of 2015, 2016, and 2019, respectively. The fully phase-covered light curves and radial ve…
Multi-scale Radio and X-Ray Structure of the High-redshift Quasar PMN J0909+0354
Paragi, Zsolt; Frey, Sándor; Perger, Krisztina +3 more
The high-redshift quasar PMN J0909+0354 (z = 3.288) is known to have a parsec-scale compact jet structure, based on global 5 GHz very long baseline interferometry (VLBI) observations performed in 1992. Its kiloparsec-scale structure was studied with the Karl G. Jansky Very Large Array (VLA) in the radio and the Chandra space telescope in X-rays. A…
Further Adventures in Mars DTM Quality: Smoothing Errors, Sharpening Details
Kirk, R. L.; Gwinner, K.; Fergason, R. L. +4 more
We have used high-precision, high-resolution digital terrain models (DTMs) of the NASA Mars Science Laboratory and Mars 2020 rover landing sites based on mosaicked images from the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (MRO HiRISE) camera as a reference data set to evaluate DTMs based on Mars Express High Resolution…