Search Publications
SN 2019hcc: a Type II supernova displaying early O II lines
Gromadzki, Mariusz; Pignata, Giuliano; Galbany, Lluis +18 more
We present optical spectroscopy together with ultraviolet, optical, and near-infrared photometry of SN 2019hcc, which resides in a host galaxy at redshift 0.044, displaying a sub-solar metallicity. The supernova spectrum near peak epoch shows a 'w' shape at around 4000 Å which is usually associated with O II lines and is typical of Type I superlum…
The wide upper main sequence and main-sequence turnoff of the ∼ 800 Myr old star cluster NGC 1831
Bellini, Andrea; Goudfrooij, Paul; Correnti, Matteo +1 more
We present the analysis of the colour-magnitude diagram (CMD) morphology of the ~800 Myr old star cluster NGC 1831 in the Large Magellanic Cloud, exploiting deep, high-resolution photometry obtained using the Wide Field Camera 3 onboard the Hubble Space Telescope. We perform a simultaneous analysis of the wide upper main sequence and main-sequence…
A differential RR Lyrae line-of-sight distance between M31 and M33
Sarajedini, Ata
We present a purely differential line-of-sight distance between M31 and M33 using ab-type RR Lyrae variables observed in each galaxy by the Hubble Space Telescope Advanced Camera for Surveys in the F606W filter. Using 1481 RR Lyraes in 13 M31 fields and 181 RR Lyraes in 6 M33 fields, and placing all of these stars on a uniform photometric scale wi…
Imaging results from the legacy Giant Metrewave Radio Telescope Galaxy Cluster Key Project
Kale, Ruta; Wadadekar, Yogesh; George, Lijo T.
We have used archival Giant Metrewave Radio Telescope (GMRT) data to image and study 39 galaxy clusters. These observations were made as part of the GMRT Key Project on galaxy clusters between 2001 and 2004. The observations presented in this sample include 14 observations at 610 MHz, 29 at 325 MHz, and three at 244 MHz covering a redshift range o…
A warm molecular ring in AG Car: composing the mass-loss puzzle
Umana, G.; Loru, S.; Rizzo, J. R. +9 more
We present APEX observations of CO J = 3 → 2 and ALMA observations of CO J = 2 → 1, 13CO J = 2 → 1, and continuum towards the Galactic luminous blue variable AG Car. These new observations reveal the presence of a ring-like molecular structure surrounding the star. Morphology and kinematics of the gas are consistent with a slowly expand…
Polarimetric and photometric observations of CB54, with analysis of four other dark clouds
Sen, A. K.; Il'in, V. B.; Prokopjeva, M. S. +1 more
We present the results of our BVR-band photometric and R-band polarimetric observations of ∼40 stars in the periphery of the dark cloud CB54. From different photometric data, we estimate E(B - V) and E(J - H). After involving data from other sources, we discuss the extinction variations towards CB54. We reveal two main dust layers: a foreground, E…
Exotic image formation in strong gravitational lensing by clusters of galaxies - II. Uncertainties
Ghosh, Agniva; Williams, Liliya L. R.; Meena, Ashish Kumar +1 more
Due to the finite amount of observational data, the best-fitting parameters corresponding to the reconstructed cluster mass have uncertainties. In turn, these uncertainties affect the inferences made from these mass models. Following our earlier work, we have studied the effect of such uncertainties on the singularity maps in simulated and actual …
Discovery of new mercury-manganese stars, including a fast rotator
Nuñez, N. E.; González, J. F.; Veramendi, M. E. +3 more
The origin of mercury-manganese (HgMn) stars is still poorly understood and the statistical analysis of an extensive sample of well characterized objects would be very valuable. Nevertheless, the compilation of a clean and reliable list of all known HgMn stars, and complete characterization of those objects, is still a pending issue. We report the…
UV spectroscopy confirms SU Lyn to be a symbiotic star
Joshi, Vishal; Kumar, Vipin; Srivastava, Mudit K. +1 more
SU Lyn, a star that ostensibly appears to be an unremarkable late M type giant, has recently been proposed to be a symbiotic star largely based on its hard X-ray properties. The star does not display, in low-resolution optical spectra, the high excitation lines typically seen in the spectra of symbiotic stars. In this work, ultraviolet (UV), optic…
IllustrisTNG and S2COSMOS: possible conflicts in the evolution of neutral gas and dust
Smith, Matthew W. L.; Gomez, Haley L.; Millard, Jenifer S. +3 more
We investigate the evolution in galactic dust mass over cosmic time through (i) empirically derived dust masses using stacked submillimetre fluxes at 850 µm in the COSMOS field and (ii) dust masses derived using a robust post-processing method on the results from the cosmological hydrodynamical simulation IllustrisTNG. We effectively perform…