Search Publications
Interplay of dust alignment, grain growth, and magnetic fields in polarization: lessons from the emission-to-extinction ratio
Boulanger, F.; Guillet, V.; Jones, A. P. +1 more
Context. Polarized extinction and emission from dust in the interstellar medium (ISM) are hard to interpret, as their dependence on dust optical properties, grain alignment, and magnetic field orientation is complex. This is particularly true in molecular clouds. The aforementioned phenomena are usually considered independently in polarization stu…
A Catalog Sample of Low-mass Galaxies Observed in X-Rays with Central Candidate Black Holes
Nucita, A. A.; De Paolis, F.; Ingrosso, G. +2 more
We present a sample of X-ray-selected candidate black holes in 51 low-mass galaxies with z ≤ 0.055 and masses up to 1010 M ⊙ obtained by cross-correlating the NASA-SLOAN Atlas with the 3XMM catalog. We have also searched in the available catalogs for radio counterparts of the black hole candidates and find that 19 of the prev…
Phase relationship between ULF waves and drift-bounce resonant ions: A statistical study
Zong, Q. G.; Rankin, R.; Wang, Y. F. +4 more
We explore the phase relationship between the poloidal mode ULF wave electric field oscillations and drift-bounce resonant oxygen ions under the resonant condition of N = 2 at the magnetic equator. Using Cluster data from 2001 to 2004, we identify 55 fundamental poloidal mode wave events, among which 42 show "negative slope" pitch angle dispersion…
Abundances of the light elements from UV (HST) and red (ESO) spectra in the very old star HD 84937
Spite, M.; Barbuy, B.; Spite, F. +2 more
Aims: In order to provide a better basis for the study of mechanisms of nucleosynthesis of the light elements beyond hydrogen and helium in the oldest stars, the abundances of C, O, Mg, Si, P, S, K, and Ca have been derived from UV-HST and visible-ESO high resolution spectra in the old, very metal-poor star HD 84937, at a metallicity that is …
AGILE Observations of the Gravitational-wave Source GW170817: Constraining Gamma-Ray Emission from an NS-NS Coalescence
Antonelli, L. A.; Costa, E.; Barbiellini, G. +39 more
The LIGO-Virgo Collaboration (LVC) detected, on 2017 August 17, an exceptional gravitational-wave (GW) event temporally consistent within ∼ 1.7 {{s}} with the GRB 1708117A observed by Fermi-GBM and INTEGRAL. The event turns out to be compatible with a neutron star-neutron star (NS-NS) coalescence that subsequently produced a radio/optical/X-ray tr…
Redshift remapping and cosmic acceleration in dark-matter-dominated cosmological models
Prada, Francisco; Wojtak, Radosław
The standard relation between the cosmological redshift and cosmic scalefactor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the Λ cold-dark-matter (ΛCDM) cosmological model. This relation is not a fundamental theory and thus observational determination of this function (redshif…
The Structure of the Young Star Cluster NGC 6231. I. Stellar Population
Gromadzki, Mariusz; Feigelson, Eric D.; Getman, Konstantin V. +4 more
NGC 6231 is a young cluster (age ∼2-7 Myr) dominating the Sco OB1 association (distance ∼1.59 kpc) with ∼100 O and B stars and a large pre-main-sequence stellar population. We combine a reanalysis of archival Chandra X-ray data with multiepoch near-infrared (NIR) photometry from the VISTA Variables in the Vía Lactéa (VVV) survey and published opti…
The complex, dusty narrow-line region of NGC 4388: gas-jet interactions, outflows and extinction revealed by near-IR spectroscopy
Colina, L.; Ho, L. C.; Winge, C. +14 more
We present Gemini/GNIRS (Gemini Near-Infrared Spectrograph) spectroscopy of the Seyfert 2 galaxy NGC 4388, with simultaneous coverage from 0.85 to 2.5 µm. Several spatially extended emission lines are detected for the first time, both in the obscured and unobscured portion of the optical narrow-line region (NLR), allowing us to assess the co…
Discovery of a Very Bright and Intrinsically Very Luminous, Strongly Lensed Lyα Emitting Galaxy at z = 2.82 in the BOSS Emission-Line Lens Survey
Brownstein, Joel R.; Marques-Chaves, Rui; Oguri, Masamune +9 more
We report the discovery of a very bright (r = 20.16), highly magnified, and yet intrinsically very luminous Lyα emitter (LAE) at z=2.82. This system comprises four images in the observer plane with a maximum separation of ∼ 6\prime\prime and it is lensed by a z=0.55 massive early-type galaxy. It was initially identified in the Baryon Os…
The protoplanetary system HD 100546 in Hα polarized light from SPHERE/ZIMPOL. A bar-like structure across the disk gap?
Lumsden, S. L.; Mendigutía, I.; Huélamo, N. +7 more
Context. HD 100546 is one of the few known pre-main-sequence stars that may host a planetary system in its disk.
Aims: This work aims to contribute to our understanding of HD 100546 by analyzing new polarimetric images with high spatial resolution.
Methods: Using VLT/SPHERE/ZIMPOL with two filters in Hα and the adjacent continuum, we hav…