Search Publications
Time-variable diffuse γ-ray foreground
Siegert, Thomas
While the data analysis of γ-ray telescopes has now become more robust, some signals may be misinterpretations of a time-variable foreground emission from the Solar system, induced by low-energy cosmic-ray interactions with asteroids. Our goal is to provide emission templates for this time-variable diffuse γ-ray foreground by considering the popul…
Common origin of trapped volatiles in oxidized icy moons and comets
Johnson, Robert E.; Oza, Apurva V.
Following spacecraft encounters with comets 67P/C-G and 1P/Halley, it was surprising that O2, expected to be a very minor species in their comas, was observed to outgas at a few percent abundance during their ice sublimation phases. This challenged the direct connection suggested between comets and material in the interstellar medium (I…
Measurement of the Taylor Microscale and the Effective Magnetic Reynolds Number in the Solar Wind With Cluster
Nakamura, R.; Narita, Y.; Matthaeus, W. H. +6 more
We use magnetic field data from the Cluster mission to estimate the value of the Taylor microscale and the effective magnetic Reynolds number in the interplanetary solar wind. Turbulent cascades can be characterized by the spatial scale at which dissipation begins to impact the local energy transfer, estimated by the Taylor microscale, as well as …
Quiescent black hole X-ray binaries as multi-messenger sources
Calore, Francesca; Kantzas, Dimitrios
The origin of Galactic cosmic rays (CRs) is unknown even though they have traditionally been connected to supernovae based on energetic arguments. In the past decades, Galactic black holes in X-ray binaries (BHXBs) have been proposed as candidate sources of CRs, which revises the CR paradigm. BHXBs launch two relativistic jets during their outburs…
The Gaia-ESO Survey: No sign of multiple stellar populations in open clusters from their sodium and oxygen abundances
Baratella, M.; Randich, S.; Bragaglia, A. +9 more
Context. The light element (anti-)correlations shown by globular clusters (GCs) are the main spectroscopic signature of multiple stellar populations. These internal abundance variations provide us with fundamental constraints on the formation mechanism of stellar clusters.
Aims: Using Gaia-ESO, the largest and most homogeneous survey of open …
Unveiling the nature of two dwarf novae: CRTS J080846.2+313106 and V416 Dra
Scaringi, Simone; Schwope, Axel; Anupama, G. C. +8 more
We present the analysis of optical photometric and spectroscopic observations of two non-magnetic cataclysmic variables, namely CRTS J080846.2+313106 and V416 Dra. We find CRTS J080846.2+313106 to vary with a period of 4.9116 ± 0.0003 h, which was not found in earlier studies and which we provisionally suggest is the orbital period of the system. …
Bright-rimmed clouds in IC 1396: I. Dynamics
Güsten, Rolf; Ishihara, Daisuke; Okada, Yoko +14 more
Aims. We investigate the dynamical and physical structures of bright-rimmed clouds (BRCs) in a nearby H II region. We focused on carbon- and oxygen-bearing species that trace photon-dominated regions (PDRs) and warm molecular cloud surfaces in order to understand the effect of UV radiation from the exciting stars on the cloud structure. Methods. W…
Cold quasar investigation: comparing star formation rates to black hole growth
Kirkpatrick, Allison; Coleman, Brandon; Mintz, Sasha
Cold quasars are a rare population of luminous, unobscured quasars associated with host galaxies that have a high star formation rate. We aimed to study the host galaxies of 64 of these cold quasars in order to probe how the supermassive black holes and host galaxies were co-evolving. We compiled data from the XMM-XXL survey and cross-matched with…
Possibilities of identifying members from Milky Way satellite galaxies using unsupervised machine learning algorithms
Sivarani, Thirupathi; Divakar, Devika K.; Doddamani, Vijayakumar H. +1 more
A detailed study of stellar populations in Milky Way (MW) satellite galaxies remains an observational challenge due to their faintness and fewer spectroscopically confirmed member stars. We use unsupervised machine learning methods to identify new members for nine nearby MW satellite galaxies using Gaia data release-3 (Gaia DR3) astrometry, the Da…
A Perfect Tidal Storm: HD 104067 Planetary Architecture Creating an Incandescent World
Kane, Stephen R.; Howard, Andrew W.; Fetherolf, Tara +5 more
The discovery of planetary systems beyond the solar system has revealed a diversity of architectures, most of which differ significantly from our system. The initial detection of an exoplanet is often followed by subsequent discoveries within the same system as observations continue, measurement precision is improved, or additional techniques are …