Search Publications
The oldest stars with low neutron-capture element abundances and origins in ancient dwarf galaxies
Frebel, Anna; Andales, Hillary Diane; Santos Figueiredo, Ananda +2 more
We present a detailed chemical abundance and kinematic analysis of six extremely metal-poor (-4.2 ≤ [Fe/H] ≤-2.9) halo stars with very low neutron-capture abundances ([Sr/H] and [Ba/H]) based on high-resolution Magellan/MIKE spectra. Three of our stars have [Sr/Ba] and [Sr/H] ratios that resemble those of metal-poor stars in ultra-faint dwarf gala…
The effects of stellar feedback on molecular clumps in the Lagoon Nebula (M8)
Wyrowski, Friedrich; Menten, Karl M.; Kahle, K. Angelique +3 more
Context. The Lagoon Nebula (M8) is host to multiple regions with recent and ongoing massive star formation, due to which it appears as one of the brightest H II regions in the sky. M8-Main and M8 East, two prominent regions of massive star formation, have been studied in detail over the past few years, while large parts of the nebula and its surro…
Parallax Effect in Microlensing Events Due to Free-floating Planets
Sangtarash, Parisa; Sajadian, Sedighe
One of the most important applications of microlensing observations is the detection of free-floating planets (FFPs). The timescale of microlensing due to FFPs (t E) is short (a few days). Discerning the annual parallax effect in observations of these short-duration events due to FFPs by one observer is barely possible, though their par…
Study of solar brightness profiles in the 18-26 GHz frequency range with INAF radio telescopes. II. Evidence of coronal emission
Sasso, C.; Romoli, M.; Iacolina, M. N. +43 more
Context. One of the most important objectives of solar physics is to gain a physical understanding of the solar atmosphere, whose structure can also be described in terms of the density (N) and temperature (T) distributions of the atmospheric matter. Several multi-frequency analyses have shown that the characteristics of these distributions are st…
DESI Massive Poststarburst Galaxies at z ∼ 1.2 Have Compact Structures and Dense Cores
Miquel, Ramon; Sanchez, Eusebio; Bezanson, Rachel +34 more
Poststarburst galaxies (PSBs) are young quiescent galaxies that have recently experienced a rapid decrease in star formation, allowing us to probe the fast-quenching period of galaxy evolution. In this work, we obtained Hubble Space Telescope (HST)/WFC3 F110W imaging to measure the sizes of 171 massive (
Integrated Study of X-Ray Spectrum and Time Lags for HBL Mrk 421 within the Framework of the Multiple-zone Leptonic Model
Xiao, Guang-Cheng; Hu, Wen; Kang, Jia-Lai +3 more
We present the timing analysis of 10 archived XMM-Newton observations with an exposure of >40 ks of Markarian 421. Mrk 421 is the brightest high-frequency-peaked BL Lac object emitting in X-rays produced by electrons accelerated in the innermost regions of a relativistic jet pointing toward us. For each observation, we construct averaged X-ray …
Massive compact quiescent galaxies in the M⋆ versus σe plane: insights from stellar population properties
Clerici, K. Slodkowski; Schnorr-Müller, A.; Trevisan, M. +1 more
We investigated the stellar population properties of a sample of 1858 massive compact galaxies (MCGs) extracted from the Sloan Digital Sky Survey (SDSS). Motivated by previous results showing that older compact galaxies tend to have larger velocity dispersion at fixed stellar mass, we used the distance to the σe versus Re and…
On the morphology of open clusters probed by ASteCA using Gaia data
Pera, M. S.; Perrén, G. I.; Navone, H. D. +1 more
We analyze the morphology of over 1000 open clusters scattered in the third and fourth quadrants of the Galaxy, obtaining estimates for their projected two-dimensional ellipticities and rotation angles. Both parameters are closely linked to the formation process and dynamical evolution of these objects. We employed a Bayesian inference method comb…
Efficiency of Nonthermal Pulsed Emission from Eight MeV Pulsars
Takata, J.; Wang, H. -H.; Lin, L. C. -C., +1 more
We report on the properties of pulsed X-ray emission from eight MeV pulsars using XMM-Newton, NICER, NuSTAR, and HXMT data. For five of the eight MeV pulsars, the X-ray spectra can be fit by a broken power-law model with a break energy of ∼5–10 keV. The photon indices below and above the break energy are ∼1 and ∼1.5, respectively. In comparison wi…
Spatial Variations and Breaks in the Optical–Near-infrared Spectra of the Pulsar and Pulsar Wind Nebula in Supernova Remnant 0540–69.3
Tenhu, L.; Larsson, J.; Sollerman, J. +4 more
The supernova remnant (SNR) 0540–69.3, twin of the Crab Nebula, offers an excellent opportunity to study the continuum emission from a young pulsar and pulsar wind nebula (PWN). We present observations taken with the Very Large Telescope instruments MUSE and X-shooter in the wavelength range 3000–25000 Å, which allow us to study spatial variations…