Search Publications
Soft excess in the quiescent Be/X-ray pulsar RX J0812.4-3114
Ho, Wynn C. G.; Potekhin, Alexander Y.; Heinke, Craig O. +3 more
We report a 72 ks XMM-Newton observation of the Be/X-ray pulsar (BeXRP) RX J0812.4-3114 in quiescence (L_X ≈ 1.6× 10^{33} erg s^{-1}). Intriguingly, we find a two-component spectrum, with a hard power-law (Γ ≈ 1.5) and a soft blackbody-like excess below ≈1 keV. The blackbody component is consistent in kT with a prior quiescent Chandra observation …
Variable Warm Dust around the Herbig Ae Star HD 169142: Birth of a Ring?
Weigelt, Gerd; Moór, Attila; Kóspál, Ágnes +7 more
The Herbig Ae star HD 169142 is known to have a gaseous disk with a large inner hole, and also a photometrically variable inner dust component in the sub-astronomical-unit region. Following up on our previous analysis, we further studied the temporal evolution of inner dust around HD 169142, which may provide information on the evolution from late…
Variable Hard X-Ray Emission from the Central Star of the Eskimo Nebula
Toalá, Jesús A.; Guerrero, Martín A.; Chu, You-Hua
The central star of NGC 2392 shows the hardest X-ray emission among central stars of planetary nebulae (CSPNe). The recent discovery of a spectroscopic companion with an orbital period of 1.9 days could provide an explanation for its hard X-ray emission, as well as for the collimation of its fast outflow. Here, we analyze the available Chandra and…
Near-infrared Variability of Low-mass Stars in IC 1396A and Tr 37
Rieke, G. H.; Hodapp, Klaus W.; Meng, Huan Y. A. +5 more
We have monitored nearly a square degree in IC 1396A/Tr 37 over 21 epochs extending over 2014-2016 for sources variable in the JHK bands. In our data, 65% ± 8% of previously identified cluster members show variations, compared with ≲0.3% of field stars. We identify 119 members of Tr 37 on the basis of variability, forming an unbiased sample down t…
Progressive steepening of the SNR RX J1713.7-3946 X-ray spectrum from XMM-Newton to INTEGRAL
Churazov, Eugene; Krivonos, Roman; Kuznetsova, Ekaterina +2 more
In this work, we present the first detailed analysis of the supernova remnant RX J1713.7-3946 in the hard X-ray energy range with the Imager on Board the INTEGRAL Satellite (IBIS) coded-mask telescope onboard the INTEGRAL observatory. The shell-type morphology of the entire remnant is mapped in hard X-rays for the first time and significantly dete…
Extremely High Plasma Densities in the Mars Ionosphere Associated With Cusp-Like Magnetic Fields
Fallows, K.; Withers, P.; Kopf, A. +1 more
The Martian crustal magnetic field modifies the structure of the ionosphere, the loss of atmosphere to space, and the interactions of the upper atmosphere with the solar wind. The Mars Advanced Radar for Subsurface and Ionosphere Sounding topside sounder on Mars Express has regularly observed oblique echoes from magnetically controlled plasma stru…
Gemini IFU, VLA, and HST observations of the OH Megamaser Galaxy IRAS17526 + 3253
Storchi-Bergmann, T.; Robinson, A.; Riffel, R. A. +7 more
We present a multiwavelength study of the OH megamaser galaxy IRAS17526 + 3253, based on new Gemini multi-object spectrograph integral field unit (GMOS/IFU) observations, Hubble Space Telescope F814W, and H α + [N II] images, and archival 2MASS and 1.49 GHz VLA data. The Hubble Space Telescope(HST) images clearly reveal a mid-to-advanced stage maj…
Compact Galaxies at intermediate redshifts quench faster than normal-sized Galaxies
Menéndez-Delmestre, K.; Charbonnier, A.; Gonçalves, T. S. +2 more
Massive quiescent compact galaxies have been discovered at high redshifts, associated with rapid compaction and cessation of star formation (SF). In this work, we set out to quantify the time-scales in which SF is quenched in compact galaxies at intermediate redshifts. For this, we select a sample of green valley galaxies within the COSMOS field i…
Mode of accretion in episodic radio galaxies and the dynamics of their outer relic lobes
Hota, Ananda; Hardcastle, M. J.; Croston, J. H. +3 more
We present X-ray observations with the X-ray Multi-Mirror Mission Newton telescope of three double-double radio galaxies (DDRGs). We have detected the core, lobes, and environment of our sample DDRGs in X-rays. We examine the relationships between the radio and X-ray emission and attribute the X-ray emission from the lobes to the inverse Compton s…
The OTELO survey. III. Demography, morphology, IR luminosity and environment of AGN hosts
Gallego, Jesús; Sánchez-Portal, Miguel; Pintos-Castro, Irene +16 more
Aims: We take advantage of the capabilities of the OSIRIS Tunable Emission Line Object (OTELO) survey to select and study the AGN population in the field. In particular, we aim to perform an analysis of the properties of these objects, including their demography, morphology, and IR luminosity. Focusing on the population of Hα emitters at z ∼ …