Search Publications
CRTS J035010.7 + 323230, a new eclipsing polar in the cataclysmic variable period gap
Szkody, Paula; Mason, Paul A.; Wells, Natalie K. +2 more
We report the discovery of a new eclipsing polar, CRTS J035010.7+323230 (hereafter CRTS J0350+3232). We identified this cataclysmic variable (CV) candidate as a possible polar from its multiyear Catalina Real-Time Transient Survey (CRTS) optical light curve. Photometric monitoring of 22 eclipses in 2015 and 2017 was performed with the 2.1-m Otto S…
A young and obscured AGN embedded in the giant radio galaxy Mrk 1498
Jiménez-Andrade, E. F.; Ubertini, P.; Chavushyan, V. +10 more
Mrk 1498 is part of a sample of galaxies with extended emission-line regions (extended outwards up to a distance of ∼7 kpc) suggested to be photoionized by an AGN that has faded away or that is still active but heavily absorbed. Interestingly, the nucleus of Mrk 1498 is at the centre of two giant radio lobes with a projected linear size of 1.1 Mpc…
Evidence of a large-scale positive rotation-metallicity correlation in the Galactic thick disc
Lattanzi, Mario G.; Re Fiorentin, Paola; Spagna, Alessandro
This study is based on high quality astrometric and spectroscopic data from the most recent releases by Gaia and APOGEE. We select 58 882 thin and thick disc red giants in the Galactocentric (cylindrical) distance range 5 < R < 13 kpc and within |z| < 3 kpc, for which full chemo-kinematical information is available. Radial chemical gradie…
Member Stars of the GD-1 Tidal Stream from the SDSS, LAMOST, and Gaia Surveys
Huang, Y.; Chen, B. -Q.; Wang, C. +5 more
With the photometric data from the SDSS survey, the spectroscopic data from the SDSS/SEGUE and the LAMOST surveys, and the astrometric data from the Gaia DR2, we have identified 67 highly probable member stars of the GD-1 cold stellar stream spread along almost its entire length (i.e., from 126° to 203° in R.A.). With the accurate spectroscopic (i…
Carbon-deficient Red Giants
Bond, Howard E.
Carbon-deficient red giants (CDRGs) are a rare class of peculiar red giants, also called “weak G-band” or “weak CH” stars. Their atmospheric compositions show depleted carbon, a low {}12{{C}}{/}13{{C}} isotopic ratio, and an overabundance of nitrogen, indicating that the material at the surface has undergone CN-cycle hydrogen…
Circumnuclear Rings and Lindblad Resonances in Spiral Galaxies
Díaz, R. J.; Agüero, M. P.; Gaspar, G. +5 more
In order to study the location of circumnuclear rings (CNR) and their possible relation with the inner Lindblad resonances (ILR), we investigate a sample of spiral galaxies. For this purpose, we have obtained and analyzed medium resolution spectra of five spiral galaxies in the range 6200-6900 Å. Through the Hα emission line, we constructed the ra…
On Geometrical Invariants of the Magnetic Field Gradient Tensor in Turbulent Space Plasmas: Scale Variability in the Inertial Range
Marcucci, Maria Federica; Consolini, Giuseppe; Materassi, Massimo +1 more
In a recent paper, Consolini et al. investigated the statistics of geometrical invariants of the coarse-grained gradient tensor of plasma velocity for a case study of space plasma turbulence. They showed how, at spatial scales near the proton inertial length, there is evidence for the occurrence of dissipation structures along the Vieillefosse’s t…
Detailed X-ray spectroscopy of the magnetar 1E 2259+586
Tiengo, A.; Israel, G.; Mereghetti, S. +7 more
Magnetic field geometry is expected to play a fundamental role in magnetar activity. The discovery of a phase-variable absorption feature in the X-ray spectrum of SGR 0418+5729, interpreted as cyclotron resonant scattering, suggests the presence of very strong non-dipolar components in the magnetic fields of magnetars. We performed a deep XMM-Newt…
Kinetic Analysis of the Energy Transport of Two-Flow Components in the Plasma Sheet
Cao, Jin-Bin; Ren, Ganming; Ma, Yuduan
Satellite observations indicate that multiple components often exist in the plasma sheet, particularly during impulsive fast flow events. In this paper, we perform a kinetic analysis of the energy transport of plasma sheet ion flow using a model of two-component plasma sheet ion flows (Background convection flow represented by subscript "b" and Fa…
New powerful outburst of the unusual young star V1318 Cygni S (LkHα 225)
Magakian, T. Yu.; Movsessian, T. A.; Andreasyan, H. R. +1 more
Aims: Young double star V1318 Cyg, which is associated with a small isolated star-forming region around HAeBe star BD+40°4124, has very unusual photometric and spectral behavior. We present results of photometric and spectroscopic observations in the optical range.
Methods: We carried out BVRI CCD photometric observations of V1318 Cyg fr…