Search Publications
A Search for an Optical Counterpart to the Gravitational-wave Event GW151226
Della Valle, M.; Sollerman, J.; Gal-Yam, A. +37 more
We present a search for an electromagnetic counterpart of the gravitational-wave source GW151226. Using the Pan-STARRS1 telescope we mapped out 290 square degrees in the optical I P1 filter, starting 11.5 hr after the LIGO information release and lasting for an additional 28 days. The first observations started 49.5 hr after the time of…
The SOPHIE search for northern extrasolar planets. IX. Populating the brown dwarf desert
Bouchy, F.; Deleuil, M.; Moutou, C. +20 more
Radial velocity planet search surveys of nearby solar-type stars have shown a strong scarcity of brown dwarf companions within ~5 AU. There is presently no comprehensive explanation for this lack of brown dwarf companions; therefore, increasing the sample of such objects is crucial to understand their formation and evolution. Based on precise radi…
The Hubble Space Telescope UV Legacy Survey of Galactic globular clusters - X. The radial distribution of stellar populations in NGC 2808
Milone, A. P.; Bedin, L. R.; Piotto, G. +4 more
Due to their extreme helium abundance, the multiple stellar populations of the globular cluster NGC 2808 have been widely investigated from a photometric, spectroscopic, and kinematic perspective. The most striking feature of the colour-magnitude diagram of NGC 2808 is the triple main sequence (MS), with the red MS corresponding to a stellar popul…
Lighting the Dark Molecular Gas: H2 as a Direct Tracer
Togi, Aditya; Smith, J. D. T.
Robust knowledge of molecular gas mass is critical for understanding star formation in galaxies. The {{{H}}}2 molecule does not emit efficiently in the cold interstellar medium, hence the molecular gas content of galaxies is typically inferred using indirect tracers. At low metallicity and in other extreme environments, these tracers ca…
Extreme star formation events in quasar hosts over 0.5 < z < 4
Wang, L.; Feltre, A.; Hatziminaoglou, E. +7 more
We explore the relationship between active galactic nuclei (AGN) and star formation in a sample of 513 optically luminous type 1 quasars up to redshifts of ∼4 hosting extremely high star formation rates (SFRs). The quasars are selected to be individually detected by the Herschel SPIRE instrument at >3σ at 250 µm, leading to typical SFRs o…
Towards the statistical detection of the warm-hot intergalactic medium in intercluster filaments of the cosmic web
Prochaska, J. Xavier; Tejos, Nicolas; Morris, Simon L. +6 more
Modern analyses of structure formation predict a universe tangled in a `cosmic web' of dark matter and diffuse baryons. These theories further predict that at low z, a significant fraction of the baryons will be shock-heated to T ∼ 105-107 K yielding a warm-hot intergalactic medium (WHIM), but whose actual existence has elude…
Rotation curve and mass distribution in the Galaxy from the velocities of objects at distances up to 200 kpc
Bobylev, V. V.; Bajkova, A. T.
Three three-component (bulge, disk, halo) model Galactic gravitational potentials differing by the expression for the dark matter halo are considered. The central (bulge) and disk components are described by the Miyamoto-Nagai expressions. The Allen-Santillán (I), Wilkinson-Evans (II), and Navarro-Frenk-White (III) models are used to describe the …
Discovery of a fast, broad, transient outflow in NGC 985
Kaastra, J. S.; Kriss, G. A.; Ebrero, J. +1 more
Aims: We observed the Seyfert 1 galaxy NGC 985 on several occasions to search for variability in its UV and X-ray absorption features to establish their location and physical properties.
Methods: We used XMM-Newton to obtain X-ray spectra using the EPIC-pn camera, and the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (H…
Search for compensated isocurvature perturbations with Planck power spectra
Kovetz, Ely D.; Kamionkowski, Marc; Muñoz, Julian B. +2 more
In the standard inflationary scenario, primordial perturbations are adiabatic. The amplitudes of most types of isocurvature perturbations are generally constrained by current data to be small. If, however, there is a baryon-density perturbation that is compensated by a dark-matter perturbation in such a way that the total matter density is unpertu…
DDO 68: A Flea with Smaller Fleas that on Him Prey
Aloisi, Alessandra; Cignoni, Michele; Sacchi, Elena +7 more
We present new photometry of the dwarf irregular galaxy DDO 68, one of the most metal-poor and least massive dwarfs, located in the Lynx-Cancer Void. The images were acquired with the Large Binocular Telescope in the g and r passbands and show unequivocally that DDO 68 has previously unknown stellar streams related to the accretion of at least two…