Search Publications
Near-infrared Spectroscopy of Dense Ejecta Knots in the Outer Eastern Area of the Cassiopeia A Supernova Remnant
Koo, Bon-Chul; Lee, Jae-Joon; Yoon, Sung-Chul +1 more
The Cassiopeia A supernova remnant has a complex structure, manifesting the multidimensional nature of core-collapse supernova explosions. To further understand this, we carried out near-infrared multiobject spectroscopy on the ejecta knots located in the northeastern (NE) jet and Fe K plume regions, which are two distinct features in the outer ea…
Activity distribution of comet 67P/Churyumov-Gerasimenko from combined measurements of non-gravitational forces and torques
Jorda, L.; Agarwal, J.; Groussin, O. +5 more
Aims: Understanding the activity is vital for deciphering the structure, formation, and evolution of comets. We investigate models of cometary activity by comparing them to the dynamics of 67P/Churyumov-Gerasimenko.
Methods: We matched simple thermal models of water activity to the combined Rosetta datasets by fitting to the total outgas…
Chemical abundances of the Typhon stellar stream
Ting, Yuan-Sen; Naidu, Rohan P.; Simon, Joshua D. +2 more
We present the first high-resolution chemical abundances of seven stars in the recently discovered high-energy stream Typhon. Typhon stars have apocentres r ≳ 100 kpc, making this the first detailed chemical picture of the Milky Way's very distant stellar halo. Though the sample size is limited, we find that Typhon's chemical abundances are more l…
Beyond the disk: EUV coronagraphic observations of the Extreme Ultraviolet Imager on board Solar Orbiter
Zhang, X.; Schmutz, W.; Mierla, M. +38 more
Context. Most observations of the solar corona beyond 2 R⊙ consist of broadband visible light imagery carried out with coronagraphs. The associated diagnostics mainly consist of kinematics and derivations of the electron number density. While the measurement of the properties of emission lines can provide crucial additional diagnostics …
Deuterium fractionation across the infrared-dark cloud G034.77−00.55 interacting with the supernova remnant W44
Caselli, P.; Viti, S.; Jiménez-Serra, I. +10 more
Context. Supernova remnants (SNRs) may regulate star formation in galaxies. For example, SNR-driven shocks may form new molecular gas or compress pre-existing clouds and trigger the formation of new stars.
Aims: To test this scenario, we measured the deuteration of N2H+, DfracN2H+
MeV gamma-ray constraints for light dark matter from semi-annihilation
Guo, Jun; Zhu, Bin; Wu, Lei
Exploring the realm of Dark Matter research, Light DM, which has a mass in the range of 1 MeV to 1 GeV, is a fascinating topic both theoretically and experimentally. We assume that the light dark matter is composed of complex scalars and produced from semi-annihilation, which is close to the scale of the MeV Gamma-ray satellite, allowing us to exp…
Decoding the age-chemical structure of the Milky Way disc: an application of copulas and elicitable maps
Bovy, Jo; Frankel, Neige; Leung, Henry W. +2 more
In the Milky Way, the distribution of stars in the [α/Fe] versus [Fe/H] and [Fe/H] versus age planes holds essential information about the history of star formation, accretion, and dynamical evolution of the Galactic disc. We investigate these planes by applying novel statistical methods called copulas and elicitable maps to the ages and abundance…
Forecasting the transit times of earth-directed halo CMEs using artificial neural network: A case study application with GCS forward-modeling technique
Kozarev, K.; Minta, F. N.; Elsaid, A. +2 more
Mitigating the lethal threats caused by coronal mass ejections (CMEs) on human and space operations can be accomplished with a fast and accurate forecast of Earth-directed CME transit times. The current paper presents a robust Cascade Forward Neural Network (CFNN) framework to predict the transit times of Earth-directed halo CMEs using a total of …
The unusual planetary nebula nucleus in the Galactic open cluster M37 and six further hot white dwarf candidates
Rebassa-Mansergas, Alberto; Raddi, Roberto; Torres, Santiago +6 more
Planetary nebulae in Galactic open star clusters are rare objects; only three are known to date. They are of particular interest because their distance can be determined with high accuracy, allowing one to characterize the physical properties of the planetary nebula and its ionizing central star with high confidence. Here we present the first quan…
The On-orbit Performance of the Colorado Ultraviolet Transit Experiment Mission
France, Kevin; Fleming, Brian; Nell, Nicholas +5 more
We present the on-orbit performance of the Colorado Ultraviolet Transit Experiment (CUTE). CUTE is a 6U CubeSat that launched on 2021 September 27 and is obtaining near-ultraviolet (NUV; 2480 Å-3306 Å) transit spectroscopy of short-period exoplanets. The instrument comprises a 20 cm × 8 cm rectangular Cassegrain telescope, an NUV spectrograph with…