Search Publications
The X-Ray Outburst of PG 1553+113: A Precession Effect of Two Jets in the Supermassive Black Hole Binary System
Chen, Xu; Huang, Shifeng; Yin, Hongxing +4 more
Blazar PG 1553+113 is thought to be a host of supermassive black hole binary system. A 2.2 yr quasi-periodicity in the γ-ray light curve was detected, possibly a result of jet precession. Motivated by the previous studies based on the γ-ray data, we analyzed the X-ray light curve and spectra observed during 2012-2020. The 2.2 yr quasi-periodicity …
Unraveling the inner substructure of new candidate hub-filament system in the H II region G25.4NW
Dewangan, L. K.
We present multiscale and multiwavelength data of the Galactic H II region G25.4-0.14 (hereafter G25.4NW, distance ~5.7 kpc). The SHARC-II 350-µm continuum map displays a hub-filament configuration containing five parsec-scale filaments and a central compact hub. Through the 5-GHz radio continuum map, four ionized clumps (i.e. Ia-Id) are ide…
Alternatives to Liquid Water Beneath the South Polar Ice Cap of Mars
Steinbrügge, Gregor; Schroeder, Dustin M.
Radar sounding of Mars' south polar ice cap has revealed portions of its base with stronger radar returns than its surface. These have been used to estimate high real permittivity values consistent with liquid water. However, the thermal, chemical, and geological conditions required to sustain such water bodies are challenging to achieve in the co…
3DPD: A photogrammetric pipeline for a PUSH frame stereo cameras
Cremonese, G.; Thomas, N.; Pommerol, A. +5 more
An innovative photogrammetric pipeline has been developed by INAF-Padova for the processing of the stereo images from the CaSSIS (Colour and Stereo Imaging System) (Thomas et al., 2014). CaSSIS is the multispectral stereo push frame camera on board ExoMars TGO (Trace Gas Orbiter) which will image 1.5% of the Mars surface in stereo mode with a spat…
Magnetic Fields and Star Formation around H II Regions: The S235 Complex
Ray, T. P.; Dewangan, L. K.; Luna, A. +3 more
Magnetic fields are ubiquitous and essential in star formation. In particular, their role in regulating formation of stars across diverse environments like H II regions needs to be well understood. In this study, we present magnetic field properties toward the S235 complex using near-infrared (NIR) H-band polarimetric observations, obtained with t…
Four new planetesimals around typical and pre-main-sequence stars (PLATYPUS) debris discs at 8.8 mm
Duchêne, Gaspard; Wilner, David J.; Matthews, Brenda +9 more
Millimetre continuum observations of debris discs can provide insights into the physical and dynamical properties of the unseen planetesimals that these discs host. The material properties and collisional models of planetesimals leave their signature on the grain size distribution, which can be traced through the millimetre spectral index. We pres…
Predictions of Astrometric Jitter for Sun-like Stars. I. The Model and Its Application to the Sun as Seen from the Ecliptic
Solanki, Sami K.; Shapiro, Alexander I.; Krivova, Natalie A.
The advent of Gaia, capable of measuring stellar wobbles caused by orbiting planets, raised interest in the astrometric detection of exoplanets. Another source of such wobbles (often also called jitter) is stellar magnetic activity. A quantitative assessment of the stellar astrometric jitter is important for a more reliable astrometric detection a…
Cosmography using strong-lensing systems and cosmic chronometers
Motta, V.; Lizardo, Andrés; Amante, Mario H. +2 more
Using a new sub-sample of observed strong gravitational lens systems, for the first time, we present the equation for the angular diameter distance in the y-redshift scenario for cosmography and use it to test the cosmographic parameters. In addition, we also use the observational Hubble data from cosmic chronometers and a joint analysis of both d…
FUV Observations of the Inner Coma of 46P/Wirtanen
Parker, Joel Wm.; Harris, Walter M.; Bodewits, Dennis +6 more
Far-ultraviolet observations of comets yield information about the energetic processes that dissociate the sublimated gases from their primitive surfaces. Understanding which emission processes are dominant, their effects on the observed cometary spectrum, and how to properly invert the spectrum back to the composition of the presumably pristine s…
Strong Correlation between Fe II/Mg II Ratio and Eddington Ratio of Type 1 Active Galactic Nuclei
Kim, Minjin; Nagao, Tohru; Woo, Jong-Hak +2 more
The Fe II/Mg II line flux ratio has been used as an indicator of the Fe/Mg abundance ratio in the broad-line region (BLR) of active galactic nuclei (AGNs). On the basis of archival rest-frame UV spectra obtained via the Hubble Space Telescope and the Sloan Digital Sky Survey, we investigate the Fe II/Mg II ratios of type 1 AGNs at z < 2. Over w…