Search Publications
Measuring the F-corona intensity through time correlation of total and polarized visible light images
Romoli, M.; Naletto, G.; Burtovoi, A. +4 more
We present a new correlation method for deriving the F-corona intensity distribution, which is based on the analysis of the evolution of the total and polarized visible light (VL) images. We studied the one-month variation profiles of the total and polarized brightness acquired with Large Angle Spectrometric COronagraph and found that in some regi…
Properties of IR-selected active galactic nuclei
García Lambas, D.; Alonso, M. V.; Bornancini, C. G. +1 more
Context. Active galactic nuclei (AGNs) of galaxies play an important role in the life and evolution of galaxies through the impact they exert on certain properties and on the evolutionary path of galaxies. It is well known that infrared (IR) emission is useful for selecting galaxies with AGNs, although it has been observed that there is contaminat…
Water ortho-to-para ratio in the coma of comet 67P/Churyumov-Gerasimenko
Encrenaz, T.; Erard, S.; Crovisier, J. +9 more
Context. Abundance ratios of the nuclear-spin isomers of H2O and NH3 have been measured in about two dozen comets, with a mean value corresponding to a nuclear-spin temperature of ~30 K. The real meaning of these unequilibrated nuclear-spin abundance ratios is still debated. However, an equilibrated water ortho-to-para ratio …
Evolution of pits at the surface of 67P/Churyumov-Gerasimenko
Guilbert-Lepoutre, Aurélie; Besse, Sébastien; Benseguane, Selma +6 more
Context. The observation of pits at the surface of comets offers the opportunity to take a glimpse into the properties and the mechanisms that shape a nucleus through cometary activity. If the origin of these pits is still a matter of debate, multiple studies have recently suggested that known phase transitions (such as volatile sublimation or amo…
A deeper solution to the actual geometry of CCD mosaic chips
Vienne, A.; Lin, F. R.; Peng, Q. Y. +2 more
Context. For charge-coupled device (CCD) mosaic chips in the focal plane of a large telescope, the unification for all the measurements of each chip is vital to some scientific projects, such as deep astrometric standards or construction for deeper images that can also seamlessly cover a larger area of the sky. A key part of the reduction involves…
Cloud motion and magnetic fields: Four clouds in the Cepheus Flare region
Maheswar, G.; Dib, S.; Sharma, E.
Context. The Cepheus Flare region consists of a group of dark cloud complexes that are currently active in star formation.
Aims: The aim of this work is to estimate the motions of four clouds, namely L1147/1158, L1172/1174, L1228, and L1251, located at relatively high Galactic latitude (b > 14°) in the Cepheus Flare region. We study the re…
Rapid early gas accretion for the inner Galactic disc. A case for a short accretion timescale
Khoperskov, Sergey; Di Matteo, Paola; Katz, David +3 more
Context. Recent observations of the Milky Way and galaxies at high redshifts suggest that galaxy discs were already in place soon after the Big Bang. While the gas infall history of the Milky Way in the inner disc has long been assumed to be characterised by a short accretion timescale, this has not been directly constrained using observations.
High-resolution images of two wiggling stellar jets, MHO 1502 and MHO 2147, obtained with GSAOI+GeMS
Gómez, M.; Saldaño, H. P.; Kalari, V. M. +3 more
Aims: We investigated the possible cause-effect relation between the wiggling shape of two stellar jets, MHO 1502 and MHO 2147, and the potential binarity of the respective driving stars.
Methods: We present high-angular-resolution H2 (2.122 µm) and K-band images obtained with the Gemini South Adaptive Optics Imager (GSA…
Cloud-cloud collision and star formation in G323.18+0.15
Li, Dalei; Tang, Xindi; Zhou, Jianjun +8 more
We studied the cloud-cloud collision candidate G323.18+0.15 based on signatures of induced filaments, clumps, and star formation. We used archival molecular spectrum line data from the SEDIGISM 13CO (J = 2−1) survey, from the Mopra southern Galactic plane CO survey, and infrared to radio data from the GLIMPSE, MIPS, Hi-GAL, and SGPS sur…
Pre-main sequence stars in LH 91
Panagia, N.; Beccari, G.; De Marchi, G. +3 more
Aims: We study the accretion properties of pre-main sequence (PMS) low-mass stars in the LH 91 association within the Large Magellanic Clouds.
Methods: Using optical multiband photometry obtained with the Hubble Space Telescope, we identify 75 candidates showing Hα excess emission above the 3σ level with equivalent width EWHα …