Search Publications
Discrepancies between spectroscopy and HST photometry in tagging multiple stellar populations in 22 globular clusters
Bragaglia, Angela; Carretta, Eugenio
Multiple populations (MPs) in globular clusters (GCs) are stars that are distinct for their abundances of light elements. The MPs can be directly separated by measuring abundances of C, N, O, Na, Al, and Mg with spectroscopy or indirectly from photometric sequences created by the impact of different chemistry on band passes of particular filters, …
Spectroscopic Survey of Faint Planetary-nebula Nuclei. IV. The A35-type Central Star of Pa 27
Bond, Howard E.; Zeimann, Gregory R.
We present optical spectroscopy of the 12th-magnitude central star of the planetary nebula (PN) Patchick 27 (Pa 27), obtained during a survey of faint PN nuclei (PNNs) with the Low-Resolution Spectrograph of the Hobby–Eberly Telescope. The optical spectrum of Pa 27 is that of a K0 III red giant with rotationally broadened lines. However, the star …
GRB 231115A—a Magnetar Giant Flare in the M82 Galaxy
Minaev, P. Yu.; Pozanenko, A. S.; Grebenev, S. A. +5 more
The results of a study of the short gamma-ray burst GRB 231115A in the X-ray and gamma-ray ranges are presented, based on data from the INTEGRAL and Fermi space observatories. The source of the burst is localized by the IBIS/ISGRI telescope of INTEGRAL observatory with an accuracy of ${≤}1.\!\!^'5$, it is located in the Cigar Galaxy (M 82). Early …
Disentangling the origin of chemical differences using GHOST
Angeloni, R.; Martioli, E.; Jofré, E. +8 more
Aims: We explore different scenarios to explain the chemical difference found in the remarkable giant-giant binary system HD 138202 + CD−30 12303. For the first time, we suggest how to distinguish these scenarios by taking advantage of the extensive convective envelopes of giant stars.
Methods: We carried out a high-precision determinati…
Sub-GeV dark matter annihilation: limits from Milky Way observations with INTEGRAL
Calore, Francesca; Siegert, Thomas; Serpico, Pasquale Dario
From 16 years of INTEGRAL/SPI γ-ray observations, we derive bounds on annihilating light dark matter particles in the halo of the Milky Way up to masses of about 300 MeV. We test four different spatial templates for the dark matter halo, including a Navarro-Frenk-White (NFW), Einasto, Burkert, and isothermal sphere profile, as well as three differ…
Investigating coronal loop morphology and dynamics from two vantage points
Teriaca, Luca; Solanki, Sami K.; Schühle, Udo +9 more
Coronal loops are the fundamental building blocks of the solar corona. Therefore, comprehending their properties is essential in unraveling the dynamics of the upper solar atmosphere. In this study, we conduct a comparative analysis of the morphology and dynamics of a coronal loop observed from two different spacecraft: the High Resolution Imager …
Detection of Accretion Shelves Out to the Virial Radius of a Low-mass Galaxy with JWST
van Dokkum, Pieter; Conroy, Charlie; Johnson, Benjamin D. +8 more
We report the serendipitous discovery of an extended stellar halo surrounding the low-mass galaxy Ark 227 (M * = 5 × 109 M ⊙; d = 35 Mpc) in deep JWST NIRCam imaging from the Blue Jay Survey. The F200W–F444W color provides robust star–galaxy separation, enabling the identification of stars at very low density. By c…
Episodic mass loss in the very luminous red supergiant [W60] B90 in the Large Magellanic Cloud
Udalski, A.; Boumis, P.; Boutsia, K. +6 more
Context. Despite mounting evidence that extreme red supergiants (RSGs) undergo episodic mass-loss events, their role in RSG evolution remains uncertain. Critical questions remain unanswered, such as whether or not these events can strip the star, and their timescale and frequency. Aims. This study delves into [W60] B90, one of the most luminous an…
PDRs4All. IX. Sulfur elemental abundance in the Orion Bar
Onaka, Takashi; Madden, Suzanne C.; Fuente, Asunción +31 more
Context. One of the main problems in astrochemistry is determining the amount of sulfur in volatiles and refractories in the interstellar medium. The detection of the main sulfur reservoirs (icy H2S and atomic gas) has been challenging, and estimates are based on the reliability of models to account for the abundances of species contain…
Equilibrium dynamical models in the inner region of the Large Magellanic Cloud based on Gaia DR3 kinematics
Kacharov, Nikolay; van de Ven, Glenn; Khoperskov, Sergey +3 more
Context. The Large Magellanic Cloud (LMC) contains complex dynamics driven by both internal and external processes. The external forces are due to tidal interactions with the Small Magellanic Cloud and the Milky Way, while internally its dynamics mainly depend on the stellar, gas, and dark matter mass distributions. Despite this complexity, simple…