Search Publications
Discovery of a Very Large (≈20 kpc) Galaxy at z = 3.72
Inami, Hanae; Reddy, Naveen; Dey, Arjun +12 more
We report the discovery and spectroscopic confirmation of a very large star-forming galaxy, G6025, at {z}spec} =3.721+/- 0.003. In the rest frame ≈2100 Å, G6025 subtends ≈24 kpc in physical extent when measured from the 1.5σ isophote, in agreement with the parametric size measurements that yield a half-light radius of 4.9 ± 0.5 kpc and …
Interstellar bromine abundance is consistent with cometary ices from Rosetta
Kama, M.; Ligterink, N. F. W.
Context. Cometary ices are formed during star and planet formation, and their molecular and elemental makeup can be related to the early solar system via the study of inter- and protostellar material.
Aims: We set out to place the first observational constraints on the interstellar gas-phase abundance of bromine (Br). We further aim to compar…
The First Orbital Period of a Very Bright and Fast Nova in M31: M31N 2013-01b
Mereghetti, Sandro; Salvaterra, Ruben; De Luca, Andrea +5 more
We present the first X-ray and UV/optical observations of a very bright and fast nova in the disk of M31, M31N 2013-01b. The nova reached a peak magnitude R ∼ 15 mag and decayed by 2 mag in only 3 days, making it one of the brightest and fastest novae ever detected in Andromeda. From archival multiband data we have been able to trace its fast evol…
First speckle interferometric measurements at the Observatório do Pico dos Dias of the Laboratório Nacional de Astrofísica
Borges Fernandes, M.; Guerrero, C. A.; Souza, T. B. +2 more
In this paper we present the first speckle interferometric measurements of binary stars performed at the Observatório do Pico dos Dias of the Laboratório Nacional de Astrofísica in Brazil, using the 1.60 m Perkin-Elmer telescope. In order to carry out these observations, we had to perform an opto-mechanical modification to Camera 1 of the 1.60 m t…
Discovery of a radio nebula around PSR J0855-4644
Acero, F.; Maitra, C.; Roy, S. +1 more
We report the discovery of a diffuse radio emission around PSR J0855-4644 using an upgraded GMRT (uGMRT) observation at 1.35 GHz. The radio emission is spatially coincident with the diffuse X-ray pulsar wind nebula (PWN) seen with XMM-Newton but is much larger in extent compared to the compact axisymmetric PWN seen with Chandra. The morphology of …
Simulating radiative magnetohydrodynamical flows with ASTROBEAR: implementation and applications of non-equilibrium cooling
Raymond, J. C.; Hansen, E. C.; Hartigan, P. +2 more
Radiative cooling plays a crucial role in the dynamics of many astrophysical flows, and is particularly important in the dense shocked gas within Herbig-Haro (HH) objects and stellar jets. Simulating cooling processes accurately is necessary to compare numerical simulations with existing and planned observations of HH objects, such as those from t…
Mysterious Linear Features Across Saturn's Moon Dione
Patthoff, D. Alex; Martin, Emily S.
Our mapping of the wispy terrains on Saturn's moons Dione has revealed unique linear features that are generally long (tens to hundreds of kilometers), narrow (<5 km), and brighter than the surrounding terrains. We refer to these features as linear virgae. Similar features, with a limited distribution, have been observed on Rhea. Wherever linea…
The Bursting Pulsar GRO J1744-28: the slowest transitional pulsar?
Court, J. M. C.; Altamirano, D.; Sanna, A.
GRO J1744-28 (the Bursting Pulsar) is a neutron star low-mass X-ray binary which shows highly structured X-ray variability near the end of its X-ray outbursts. In this letter we show that this variability is analogous to that seen in Transitional Millisecond Pulsars such as PSR J1023+0038: `missing link' systems consisting of a pulsar nearing the …
Star formation history: Modeling of visual binaries
Tutukov, A. V.; Kovaleva, D. A.; Malkov, O. Yu. +3 more
Most stars form in binary or multiple systems. Their evolution is defined by masses of components, orbital separation and eccentricity. In order to understand star formation and evolutionary processes, it is vital to find distributions of physical parameters of binaries.
We have carried out Monte Carlo simulations in which we simulate differe…Physical Properties of Umbral Dots Observed in Sunspots: A Hinode Observation
Mathew, Shibu K.; Yadav, Rahul
Umbral dots (UDs) are small-scale bright features observed in the umbral part of sunspots and pores. It is well established that they are manifestations of magnetoconvection phenomena inside umbrae. We study the physical properties of UDs in different sunspots and their dependence on decay rate and filling factor. We have selected high-resolution,…