Search Publications
HST Survey of the Orion Nebula Cluster in the H2O 1.4 µm Absorption Band. III. The Population of Substellar Binary Companions
Gennaro, Mario; Pueyo, Laurent; Ubeda, Leonardo +4 more
We present new results concerning the substellar binary population in the Orion Nebula Cluster (ONC). Using the Karhunen-Loève Image Projection algorithm, we have reprocessed images taken with the IR channel of the Wide Field Camera 3 mounted on the Hubble Space Telescope to unveil faint, close companions in the wings of the stellar point-spread f…
Estimating the fate of oxygen ion outflow from the high-altitude cusp
Slapak, Rikard; Schillings, Audrey; Haaland, Stein +2 more
We have investigated the oxygen escape-to-capture ratio from the high-altitude cusp regions for various geomagnetic activity levels by combining EDI and CODIF measurements from the Cluster spacecraft. Using a magnetic field model, we traced the observed oxygen ions to one of three regions: plasma sheet, solar wind beyond a distant X-line or daysid…
Gravitational potential from small-scale clustering in action space: application to Gaia Data Release 2
Yang, Tianyi; Boruah, Supranta S.; Afshordi, Niayesh
Most measurements of mass in astronomy that use kinematics of stars or gas rely on assumptions of equilibrium that are often hard to verify. Instead, we develop a novel idea that uses the clustering in action space, as a probe of the underlying gravitational potential: the correct potential should maximize small-scale clustering in the action spac…
Molecular gas in the central region of NGC 7213
Pozzi, F.; Hatziminaoglou, E.; Vignali, C. +4 more
We present a multi-wavelength study (from X-ray to mm) of the nearby low-luminosity active galactic nucleus NGC 7213. We combine the information from the different bands to characterise the source in terms of contribution from the AGN and the host-galaxy interstellar medium. This approach allows us to provide a coherent picture of the role of the …
The distances to molecular clouds in the fourth Galactic quadrant
Wang, Shu; Jiang, Biwei; Chen, Bingqiu +4 more
Distance measurements to molecular clouds are essential and important. We present directly measured distances to 169 molecular clouds in the fourth quadrant of the Milky Way. Based on the near-infrared photometry from the Two Micron All Sky Survey and the Vista Variables in the Via Lactea Survey, we select red clump stars in the overlapping direct…
Spectrophotometric calibration of low-resolution spectra
Jordi, C.; Fabricius, C.; Carrasco, J. M. +1 more
Context. Low-resolution spectroscopy is a frequently used technique. Aperture prism spectroscopy in particular is an important tool for large-scale survey observations. The ongoing ESA space mission Gaia is the currently most relevant example.
Aims: In this work we analyse the fundamental limitations of the calibration of low-resolution spect…
NuSTAR Non-detection of a Faint Active Galactic Nucleus in an Ultraluminous Infrared Galaxy with Kpc-scale Fast Wind
Kawamuro, Taiki; Toba, Yoshiki; Noda, Hirofumi +4 more
Large-scale outflows are generally considered to be possible evidence that active galactic nuclei (AGNs) can severely affect their host galaxies. Recently, an ultraluminous infrared galaxy (ULIRG) at z = 0.49, AKARI J0916248+073034, was found to have a galaxy-scale [O III] λ5007 outflow with one of the highest energy-ejection rates at z < 1.6. …
Discovery of a Rare Late-type, Low-mass Wolf-Rayet Star in the LMC
Prochaska, J. Xavier; Morrell, Nidia; Bond, Howard E. +4 more
We report the serendipitous discovery of an object, UVQS J060819.93-715737.4, with a spectrum dominated by extremely intense, narrow C II emission lines. The spectrum is similar to those of the very rare, late-type [WC11] low-mass Wolf-Rayet stars. Despite the recognition of these stars as a distinct class decades ago, there remains barely a handf…
Ion acceleration at dipolarization fronts associated with the interchange instability in Earth's magnetotail
Lu, HaoYu; Ge, YaSong; Sun, Chao
A Multiwavelength Study of the Cool Core Cluster MACS J1447.4+0827
von der Linden, A.; Hlavacek-Larrondo, J.; Allen, S. W. +8 more
Clusters of galaxies are outstanding laboratories for understanding the physics of supermassive black hole (SMBH) feedback. Here we present the first Chandra, Karl G. Jansky Very Large Array, and Hubble Space Telescope analysis of MACS J1447.4+0827 (z = 0.3755), one of the strongest cool core clusters known, in which extreme feedback from its cent…