Search Publications
High-resolution Spectroscopy and Spectropolarimetry of Selected δ-Sct Pulsating Variables
Joshi, Y. C.; Joshi, Santosh; Singh, Harinder P. +5 more
The combination of photometry, spectroscopy and spectropolarimetry of the chemically peculiar stars often aims to study the complex physical phenomena such as stellar pulsation, chemical inhomogeneity, magnetic field and their interplay with stellar atmosphere and circumstellar environment. The prime objective of this study is to determine the atm…
A Near-infrared Counterpart of 2E1613.5-5053: The Central Source in Supernova Remnant RCW103
Scholz, P.; Kaspi, V. M.; Tendulkar, S. P. +1 more
On 2016 June 22, 2E 1613.5-5053, the puzzling central compact object in supernova remnant RCW 103 emitted a magnetar-like burst. Using Director’s Discretionary Time, we observed 2E 1613.5-5053 with the Hubble Space Telescope (HST) (WFC3/IR) and we report here on the detection of a previously unseen infrared counterpart. In observations taken on 20…
Spectroscopic Evidence of Alfvén Wave Damping in the Off-limb Solar Corona
Gupta, G. R.
We investigate the off-limb active-region and quiet-Sun corona using spectroscopic data. The active region is clearly visible in several spectral lines formed in the temperature range of 1.1-2.8 MK. We derive the electron number density using the line ratio method, and the nonthermal velocity in the off-limb region up to the distance of 140 Mm. We…
Evidence of chaotic modes in the analysis of four δ Scuti stars
García, R. A.; García Hernández, A.; Roca Cortés, T. +1 more
Context. Since CoRoT observations unveiled the very low amplitude modes that form a flat plateau in the power spectrum structure of δ Scuti stars, the nature of this phenomenon, including the possibility of spurious signals due to the light curve analysis, has been a matter of long-standing scientific debate.
Aims: We contribute to this debat…
The onset of energetic particle irradiation in Class 0 protostars
Le Bourlot, J.; Favre, C.; Ceccarelli, C. +11 more
Context. The early stages of low-mass star formation are likely to be subject to intense ionization by protostellar energetic MeV particles. As a result, the surrounding gas is enriched in molecular ions, such as HCO+ and N2H+. Nonetheless, this phenomenon remains poorly understood for Class 0 objects. Recently, ba…
Imaging of diffuse H I absorption structure in the SSA22 protocluster region at z = 3.1
Ouchi, Masami; Inoue, Akio K.; Yamada, Toru +6 more
Using galaxies as background light sources to map intervening Ly α absorption is a novel approach to study the interplay among galaxies, the circumgalactic medium (CGM) and the intergalactic medium. Introducing a new measure of z = 3.1 H I Ly α absorption relative to the cosmic mean, ΔNB497, estimated from photometric data of star-forming galaxies…
Evidence for Spatially Correlated Gaia Parallax Errors in the Kepler Field
Huber, Daniel; Stello, Dennis; Pinsonneault, Marc H. +1 more
We present evidence for a spatially dependent systematic error in the first data release of Gaia parallaxes based on comparisons to asteroseismic parallaxes in the Kepler field and provide a parameterized model of the angular dependence of these systematics. We report an error of {0.059}-0.004+0.004 mas on scales of 0.°3, whi…
Measurement of the X-ray proper motion in the south-east rim of RX J1713.7-3946
Acero, Fabio; Katsuda, Satoru; Ballet, Jean +1 more
We report on the first proper motion measurement in the supernova remnant RX J1713.7-3946 using the XMM-Newton X-ray telescope on a 13 yr time interval. This expansion measurement is carried out in the south-east region of the remnant, where two sharp filament structures are observed. For the outermost filament, the proper motion is 0.75+0.05…
Ion-Ion Equilibration and Particle Distributions in a 3000 km s-1 Shock in SN 1006
Raymond, J. C.; Laming, J. M.; Blair, W. P. +1 more
SN 1006 is the most attractive target for investigating the physics of collisionless shock waves faster than 2000 {km} {{{s}}}-1. We obtained UV and optical spectra and an Hα image of a 3000 {km} {{{s}}}-1 shock driven by a clump of ejecta that has overtaken the blast wave. It is 500 km s-1 faster than the filament…
The mass-metallicity relation of AKARI-FMOS infrared galaxies at z ∼ 0.88 in the AKARI North Ecliptic Pole Deep Survey Field
Goto, Tomotsugu; Pearson, Chris; Matsuhara, Hideo +2 more
The mass, metallicity, and star formation rate (SFR) of a galaxy are crucial parameters in understanding galaxy formation and evolution. However, the relation between these parameters, (i.e., the fundamental relation) is still a matter of debate for luminous infrared (IR) galaxies, which carry a bulk of the SFR budget of the universe at z ∼ 1. We …