Search Publications
Reflection component in the Bright Atoll Source GX 9+9
Sanna, A.; Di Salvo, T.; Burderi, L. +5 more
Context. GX 9+9 (4U 1728-16) is a low mass X-ray binary source harboring a neutron star. Although it belongs to the subclass of the bright Atoll sources together with GX 9+1, GX 3+1, and GX 13+1, its broadband spectrum is poorly studied and apparently does not show reflection features in the spectrum.
Aims: To constrain the continuum well and…
Outstanding questions in magnetospheric plasma physics: The pollenzo view
Stepanova, Marina; Hesse, Michael; Delzanno, Gian Luca +6 more
Based on discussions held at a workshop in Bra-Pollenzo, Italy, this paper elaborates upon 19 outstanding questions of plasma physics in the Earth's magnetosphere. The questions are grouped according to (a) driving processes, (b) radiation belt and ring current issues, (c) auroral physics, (d) internal plasma processes, and (e) magnetosphere-ionos…
Chromosome maps of young LMC clusters: an additional case of coeval multiple populations
Martocchia, S.; Dalessandro, E.; Salaris, M. +9 more
Recent studies have revealed that the multiple populations (MPs) phenomenon does not occur only in ancient and massive Galactic globular clusters (GCs), but it is also observed in external galaxies, where GCs sample a wide age range with respect to the Milky Way. However, for a long time, it was unclear whether we were looking at the same phenomen…
X-ray absorption in INTEGRAL active galactic nuclei. Host galaxy inclination
Ubertini, P.; Malizia, A.; Bassani, L. +2 more
In this work the INTEGRAL hard X-ray selected sample of active galactic nuclei (AGN) has been used to investigate the possible contribution of absorbing material distributed within the host galaxies to the total amount of NH measured in the X-ray band. We collected all the available axial ratio measurements of the galaxies hosting our A…
An Accreting, Anomalously Low-mass Black Hole at the Center of Low-mass Galaxy IC 750
Gelfand, Joseph D.; Chen, Yan-Ping; Greenhill, Lincoln J. +5 more
We present a multiwavelength study of the active galactic nucleus in the nearby (D = 14.1 Mpc) low-mass galaxy IC 750, which has circumnuclear 22 GHz water maser emission. The masers trace a nearly edge-on, warped disk ∼0.2 pc in diameter, coincident with the compact nuclear X-ray source that lies at the base of the ∼kiloparsec-scale extended X-ra…
A MeerKAT survey of nearby nova-like cataclysmic variables
Knigge, C.; Heywood, I.; Wijers, R. A. M. J. +17 more
We present the results of MeerKAT radio observations of 11 nearby nova-like cataclysmic variables (CVs). We have detected radio emission from IM Eri, RW Sex, V3885 Sgr, and V603 Aql. While RW Sex, V3885 Sgr, and V603 Aql had been previously detected, this is the first reported radio detection of IM Eri. Our observations have doubled the sample of …
X-Ray Spectroscopy in the Microcalorimeter Era. II. A New Diagnostic on Column Density from the Case A to B Transition in H- and He-like Iron
Ferland, G. J.; Su, Y.; Chakraborty, P. +2 more
The Soft X-ray Spectrometer on board Hitomi, with the unprecedented resolving power of R ∼ 1250, allowed the detection of members of the Fe XXV Kα complex emission spectra from the center of the Perseus Cluster. In this paper, we introduce a novel method of measuring the column density using the optically thin (Case A) to optically thick (Case B) …
Hubble Space Telescope Search for Activity in High-perihelion Objects
Mutchler, Max; Jewitt, David; Agarwal, Jessica +2 more
Solar system objects with perihelia beyond the orbit of Jupiter (q > 5 au) are too cold for water ice to generate an appreciable coma via sublimation. Despite this, numerous high-perihelion objects (HPOs) including many comets and recently escaped Kuiper Belt objects (Centaurs) are observed to be active out at least to the orbit of Saturn (q ∼ …
Kinematical investigation of possible fast collimated outflows in twelve planetary nebulae
Chu, Y. -H.; Guerrero, M. A.; Toalá, J. A. +3 more
A significant fraction of planetary nebulae (PNe) exhibit collimated outflows, distinct narrow kinematical components with notable velocity shifts with respect to the main nebular shells typically associated with low-ionization compact knots and linear or precessing jet-like features. We present here a spatio-kinematical investigation of a sample …
Constraining the Mass of the Emerging Galaxy Cluster SpARCS1049+56 at z = 1.71 with Infrared Weak Lensing
Muzzin, Adam; Perlmutter, Saul; Wilson, Gillian +4 more
In the hierarchical structure formation model of the universe, galaxy clusters are assembled through a series of mergers. Accordingly, it is expected that galaxy clusters in the early universe are actively forming and dynamically young. Located at a high redshift of z = 1.71, SpARCS1049+56 offers a unique look into the galaxy cluster formation pro…