Search Publications
GMRT H I mapping of mid-infrared bright blue compact dwarf galaxies W1016+3754 and W2326+0608
Li, D.; Tsai, C. W.; Sengupta, C. +3 more
We present the results from deep 21 cm H I mapping of two nearby Blue Compact Dwarf Galaxies (BCDGs), W1016+3754 and W2326+0608, using the Giant Metrewave Radio Telescope (GMRT). These BCDGs are bright in mid-infrared data and undergoing active star formation. With the GMRT observations, we investigate the role of cold neutral gas as the fuel reso…
Magnetic reconnection as an erosion mechanism for magnetic switchbacks
Horbury, T. S.; Louarn, P.; Owen, C. J. +3 more
Context. Magnetic switchbacks are localised polarity reversals in the radial component of the heliospheric magnetic field. Observations from Parker Solar Probe (PSP) have shown that they are a prevalent feature of the near-Sun solar wind. However, observations of switchbacks at 1 au and beyond are less frequent, suggesting that these structures ev…
Ultraviolet and Visible Reflectance Spectra of Phobos and Deimos as Measured by the ExoMars-TGO/NOMAD-UVIS Spectrometer
Vandaele, A. C.; Daerden, F.; Thomas, I. R. +18 more
Spectroscopic measurements are a powerful tool to investigate the surface composition of airless bodies and provide clues of their origin. The composition and origin of Phobos and Deimos are still unknown and are currently widely debated. We present spectroscopic measurements of Phobos and Deimos at ultraviolet and visible wavelengths (250-650 nm)…
Point-source Contribution to the Diffuse X-Ray Background below 1 keV and Its Effect on Our Understanding of the Circumgalactic Medium
Gupta, Anjali; Galeazzi, Massimiliano; Ursino, Eugenio +4 more
We studied the spectral signature of different components of the diffuse X-ray background (DXB), including Local Hot Bubble, solar wind charge exchange, galactic halo, and typically unresolved point sources (galaxies and active galactic nuclei), in the direction of the Chandra Deep Field South using the 4 Ms XMM-Newton survey and Chandra 4 Ms Sour…
Strange quasar candidates with abnormal astrometric characteristics from Gaia EDR3 and SDSS (SQUAB-II): optical identifications
Zheng, Zhen-Ya; Liao, Shilong; Qi, Zhaoxiang +7 more
There are some strange quasars with multiple Gaia detections or observed with abnormal astrometric characteristics, such as with large proper motions or significant astrometric noises. Those strange quasars could be potential candidates of quasar-star pairs, dual quasars (DQs), or lensed quasars (LQs). Searching for both DQs and LQs is of great im…
Planetary system architectures with low-mass inner planets. Direct imaging exploration of mature systems beyond 1 au
Henning, Th.; Babusiaux, C.; Messina, S. +20 more
Context. The discovery of planets orbiting at less than 1 au from their host star and less massive than Saturn in various exoplanetary systems revolutionized our theories of planetary formation. The fundamental question is whether these close-in low-mass planets could have formed in the inner disk interior to 1 au, or whether they formed further o…
Observations of Multiphase, High-velocity, Shocked Gas in the Vela Supernova Remnant
Ritchey, Adam M.
We present an analysis of high-resolution far-UV archival spectra obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope of the star HD 75309, which probes high-velocity shocked gas in the Vela supernova remnant (SNR). We examine high-velocity features from intrinsically strong absorption lines of O I, Si II, Si II*, …
12CO and 13CO observation of the low-metallicity dwarf galaxy DDO 154
Komugi, Shinya; Inaba, Miku; Shindou, Tetsuo
The conversion factor from carbon monoxide (CO) intensity to molecular gas mass is a source of large uncertainty in understanding gas and its relation to star formation in galaxies. In particular, the conversion factor in low-metallicity environments have remained elusive, as currently only two galaxies have been detected in any CO isotopes in env…
Exploring the internal rotation of the extremely low-mass He-core white dwarf GD 278 with TESS asteroseismology
Córsico, Alejandro H.; Hermes, J. J.; Althaus, Leandro G. +2 more
Context. The advent of high-quality space-based photometry, brought about by missions such as Kepler/K2 and TESS, makes it possible to unveil the fundamental parameters and properties of the interiors of white dwarf stars, particularly extremely low-mass white dwarfs, using the tools of asteroseismology.
Aims: We present an exploration of the…
Reciprocating Magnetic Fields in the Pulsar Wind Observed from the Black Widow Pulsar J1720-0534
Wang, Shen; Li, Di; Kramer, M. +41 more
We report the radio observations of the eclipsing black widow pulsar J1720-0534, a 3.26 ms pulsar in orbit with a low mass companion of mass 0.029 to 0.034 M ⊙. We obtain the phase-connected timing ephemeris and polarization profile of this millisecond pulsar (MSP) using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), …