Search Publications
New mid-infrared imaging constraints on companions and protoplanetary disks around six young stars
Waters, L. B. F. M.; Kamp, I.; Quanz, S. P. +13 more
Context. Mid-infrared (mid-IR) imaging traces the sub-micron and micron-sized dust grains in protoplanetary disks and it offers constraints on the geometrical properties of the disks and potential companions, particularly if those companions have circumplanetary disks.
Aims: We use the VISIR instrument and its upgrade NEAR on the VLT to take …
Herschel and Odin observations of H2O, CO, CH, CH+, and [N II] in the barred spiral galaxy NGC 1365. Bar-induced activity in the outer and inner circumnuclear tori
Larsson, B.; Rydbeck, G.; Frisk, U. +3 more
Context. The Odin satellite is now into its twentieth year of operation, much surpassing its design life of two years. One of its major astronomical pursuits was the search for and study of water vapor in diverse regions of the Solar System and the Milky Way galaxy. The Herschel space observatory was needed to detect water vapor in external galaxi…
Characterising atmospheric gravity waves on the nightside lower clouds of Venus: a systematic analysis
Lebonnois, S.; Machado, P.; Peralta, J. +3 more
We present the detection and characterisation of mesoscale waves on the lower clouds of Venus using images from the Visible Infrared Thermal Imaging Spectrometer onboard the European Venus Express space mission and from the 2 µm camera (IR2) instrument onboard the Japanese space mission Akatsuki. We used image navigation and processing techn…
Multi-epoch properties of the warm absorber in the Seyfert 1 galaxy NGC 985
Kaastra, J. S.; Kriss, G. A.; Ebrero, J. +1 more
Context. NGC 985 was observed by XMM-Newton twice in 2015, revealing that the source was coming out from a soft X-ray obscuration event that took place in 2013. These kinds of events are possibly recurrent since a previous XMM-Newton archival observation in 2003 also showed signatures of partial obscuration.
Aims: We have analyzed the high-re…
First detection of a disk free of volatile elements around a young A-type star: A possible sign of collisions between rocky planets
Manara, C. F.; Miles-Páez, P. A.; van den Ancker, M. E. +7 more
Aims: We present the first detailed analysis of the astrophysical parameters of the poorly studied Sco-Cen member HD 152384 and its circumstellar environment.
Methods: We analyse newly obtained optical-near-IR X-shooter spectra, as well as archival TESS data, of HD 152384. In addition, we use literature photometric data to construct a de…
The ROSAT Raster survey in the north ecliptic pole field. X-ray catalogue and optical identifications
Moneti, A.; Hasinger, G.; Capak, P. +4 more
The north ecliptic pole (NEP) is an important region for extragalactic surveys. Deep and wide contiguous surveys are being performed by several space observatories, most currently with the eROSITA telescope. Several more are planned for the near future. We analyse all the ROSAT pointed and survey observations in a region of 40 deg2 arou…
Exploring the Sun's upper atmosphere with neural networks: Reversed patterns and the hot wall effect
Asensio Ramos, A.; Socas-Navarro, H.
We have developed an inversion procedure designed for high-resolution solar spectro-polarimeters, such as those of Hinode and the DKIST. The procedure is based on artificial neural networks trained with profiles generated from random atmospheric stratifications for a high generalization capability. When applied to Hinode data, we find a hot fine-s…
Star formation around three co-moving HAeBe stars in the Cepheus Flare
Saha, P.; Maheswar, G.; Kamath, U. S. +1 more
Context. The presence of three more Herbig Ae/Be (HAeBe) candidates in the Cepheus Flare within a 1.5° radius centered on HD 200775 suggests that star formation is prevalent in a wider region of the LDN 1147/1158, LDN 1172/1174, and LDN 1177 clouds. A number of young stellar objects (YSOs) are found to be distributed toward these cloud complexes a…
The angular-momentum flux in the solar wind observed during Solar Orbiter's first orbit
Verscharen, Daniel; Bruno, Roberto; Maksimovic, Milan +20 more
Aims: We present the first measurements of the angular-momentum flux in the solar wind recorded by the Solar Orbiter spacecraft. Our aim is to validate these measurements to support future studies of the Sun's angular-momentum loss.
Methods: We combined 60-min averages of the proton bulk moments and the magnetic field measured by the Sol…
Investigation of the subsurface structure of a sunspot based on the spatial distribution of oscillation centers inferred from umbral flashes
Chae, Jongchul; Cho, Kyuhyoun; Madjarska, Maria S.
The subsurface structure of a solar sunspot is important for the stability of the sunspot and the energy transport therein. Two subsurface structure models have been proposed, the monolithic and cluster models, but no clear observational evidence supporting a particular model has been found to date. To obtain clues about the subsurface structure o…