Search Publications
Water and OH Emission from the Inner Disk of a Herbig Ae/Be Star
Najita, Joan R.; Brittain, Sean D.; Carr, John S. +2 more
We report the detection of hot H2O and OH emission from the Herbig Ae/Be star HD 101412 using the Cryogenic Infrared Echelle Spectrograph on the Very Large Telescope. Previous studies of Herbig Ae/Be stars have shown the presence of OH around some of these sources, but H2O has proven more elusive. While marginal water emissio…
Awakening of the Fast-spinning Accreting Be/X-Ray Pulsar A0538-66
Mereghetti, Sandro; Santangelo, Andrea; Ducci, Lorenzo
A0538-66 is a Be/X-ray binary (Be/XRB) hosting a 69 ms pulsar It emitted bright X-ray outbursts with peak luminosity up to ∼1039 erg s-1 during the first years after its discovery in 1977. Since then, it was always seen in quiescence or during outbursts with L x ≲ 4 × 1037 erg s-1. In 2018 we …
A Multi-epoch X-Ray Study of the Spiral Galaxy NGC 7331
Kong, Albert K. H.; Jin, Ruolan
X-ray point sources in galaxies are dominated by X-ray binaries (XRBs) that are variables or transients, and whether their variability would alter the X-ray luminosity functions (XLFs) is still in debate. Here we report on NGC 7331 as an example to test this with seven Chandra observations. Their detection limit is 7 × 1037 erg s-1…
Runaway O-star Bow Shocks as Particle Accelerators? The Case of AE Aur Revisited
Rangelov, Blagoy; Federman, S. R.; Montmerle, Thierry +2 more
We present results of our Chandra/ACIS observations of the field centered on the fast, runaway O star AE Aur and its bow shock. Previous XMM-Newton observations revealed an X-ray “blob” near the IR arc tracing the bow shock, possibly a nonthermal source consistent with models of Inverse Compton scattering of dust IR photons by electrons accelerate…
Spectroscopy of NGC 4258 Globular Cluster Candidates: Membership Confirmation and Kinematics
González-Lópezlira, Rosa A.; Georgiev, Iskren Y.; Loinard, Laurent +9 more
We present multiobject spectroscopic observations of 23 globular cluster candidates (GCCs) in the prototypical megamaser galaxy NGC 4258, carried out with the Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy instrument at the 10.4 m Gran Telescopio Canarias. The candidates have been selected based on the (u* - i‧)…
The Next Generation Fornax Survey (NGFS). V. Discovery of a Dwarf-Dwarf Galaxy Pair at z = 0.30 and Its Characterization Using Deep VLT/MUSE Observations
Grebel, Eva K.; Mieske, Steffen; Rong, Yu +11 more
We report the detection of a pair of dwarf galaxies at z = 0.30 that may be in the early stages of an interaction. Both galaxies have stellar masses of <109 M ⊙ and display a projected separation of ∼29 kpc and a physical separation of ∼240 kpc. Evidence of ongoing star formation has been found in both galaxies, with neith…
The Origins of Young Stars in the Direction of the Leading Arm of the Magellanic Stream: Abundances, Kinematics, and Orbits
Zhao, Gang; Casetti-Dinescu, Dana I.; Girard, Terrence M. +6 more
We explore the origins of the young B-type stars found by Casetti-Dinescu et al. at the outskirts of the Milky Way disk in the sky region of the Leading Arm of the Magellanic Stream. High-resolution spectroscopic observations made with the MIKE instrument on the Magellan Clay 6.5 m telescope for nine stars are added to the previous sample analyzed…
Dissecting the Hot Bubbles in LMC-N57 with XMM-Newton
Toalá, Jesús A.; Rosado, Margarita; Ramírez-Ballinas, Isidro +1 more
We present a study of the diffuse X-ray emission from the star-forming region LMC-N 57 in the Large Magellanic Cloud. We use archival XMM-Newton observations to unveil in detail the distribution of hot bubbles in this complex. X-ray emission is detected from the central superbubble (SB) DEM L 229, the supernova remnant (SNR) 0532-675, and the Wolf…
X-Ray Monitoring of the Magnetar CXOU J171405.7-381031 in Supernova Remnant CTB 37B
Gotthelf, E. V.; Halpern, J. P.; Mori, K. +1 more
We present the results of our 8 yr X-ray monitoring campaign on CXOU J171405.7-381031, the magnetar associated with the faint supernova remnant (SNR) CTB 37B. It is among the youngest by inferred spin-down age, and most energetic in spin-down power of magnetars, and may contribute, at least partially, to the GeV and TeV emission coincident with th…
Smoothed Particle Inference Analysis of SNR DEM L71
Frank, Kari A.; Burrows, David N.; Panfichi, Aldo +2 more
Supernova remnants (SNRs) are complex, three-dimensional objects; properly accounting for this complexity when modeling the resulting X-ray emission presents quite a challenge and makes it difficult to accurately characterize the properties of the full SNR volume. We apply for the first time a novel analysis method called smoothed particle inferen…