RAS_WEB (Page 3)

The Solar System: structural overview, origins and evolution Sean N. Raymond arXiv:2404.14982v1 Announce Type: new Abstract: Understanding the origin and long-term evolution of the Solar System is a fundamental goal of planetary science and astrophysics. This chapter describes our current understanding of the key processes that shaped our planetary system, informed by empirical data such as meteorite measurements, observations of planet-forming disks around other stars, and exoplanets, and nourished by theoretical modeling and laboratory experiments. The processes at play range in size from microns to gas giants, and mostly took place within the gaseous planet-forming disk through the growth of mountain-sized planetesimals and Moon- toRead More →

On the impact of the vertical structure of Martian water ice clouds on nadir atmospheric retrievals from simultaneous EMM/EXI and TGO/ACS-MIR observations Aur’elien Stcherbinine, Michael J. Wolff, Christopher S. Edwards, Oleg Korablev, Anna Fedorova, Alexander Trokhimovskiy arXiv:2404.14993v1 Announce Type: new Abstract: Retrieving the optical depth of the Martian clouds ($tau_mathrm{cld}$) is a powerful way to monitor their spatial and temporal evolution. However, such retrievals from nadir imagery rely on several assumptions, including the vertical structure of the clouds in the atmosphere. Here we compare the results of cloud optical depth retrievals from the Emirates eXploration Imager (EXI) onboard the Emirates Mars Mission (EMM) “Hope” orbiterRead More →

Solar flare observations with the Radio Neutrino Observatory Greenland (RNO-G) S. Agarwal, J. A. Aguilar, S. Ali, P. Allison, M. Betts, D. Besson, A. Bishop, O. Botner, S. Bouma, S. Buitink, M. Cataldo, B. A. Clark, A. Coleman, K. Couberly, S. de Kockere, K. D. de Vries, C. Deaconu, M. A. DuVernois, C. Glaser, T. Gl"usenkamp, A. Hallgren, S. Hallmann, J. C. Hanson, B. Hendricks, J. Henrichs, N. Heyer, C. Hornhuber, K. Hughes, T. Karg, A. Karle, J. L. Kelley, M. Korntheuer, M. Kowalski, I. Kravchenko, R. Krebs, R. Lahmann, U. Latif, P. Laub, C. -H. Liu, M. J. Marsee, Z. S. Meyers, M. Mikhailova,Read More →

Three dimensional end-to-end simulation for kilonova emission from a black-hole neutron-star merger Kyohei Kawaguchi, Nanae Domoto, Sho Fujibayashi, Kota Hayashi, Hamid Hamidani, Masaru Shibata, Masaomi Tanaka, Shinya Wanajo arXiv:2404.15027v1 Announce Type: new Abstract: We study long-term evolution of the matter ejected in a black-hole neutron-star (BH-NS) merger employing the results of a long-term numerical-relativity simulation and nucleosynthesis calculation, in which both dynamical and post-merger ejecta formation are consistently followed. In particular, we employ the results for the merger of a $1.35,M_odot$ NS and a $5.4,M_odot$ BH with the dimensionless spin of 0.75. We confirm the finding in the previous studies that thermal pressure induced byRead More →

1-bit raw voltage recording system for dedicated observations of transients at low radio frequencies Kshitij S. Bane, Indrajit V. Barve, G. V. S. Gireesh, C. Kathiravan, R. Ramesh arXiv:2404.15031v1 Announce Type: new Abstract: Recently we had reported commissioning of a prototype for pulsar observations at low radio frequencies (arXiv:2404.15031v1 Announce Type: new Abstract: Recently we had reported commissioning of a prototype for pulsar observations at low radio frequencies (Read More →

Quantum study of the CH$_3^+$ photodissociation in full dimension Neural Networks potential energy surfaces Pablo del Mazo-Sevillano, Alfredo Aguado, Javier R. Goicoechea, Octavio Roncero arXiv:2404.15032v1 Announce Type: new Abstract: CH$_3^+$, a cornerstone intermediate in interstellar chemistry, has recently been detected for the first time by the James Webb Space Telescope. The photodissociation of this ion is studied here. Accurate explicitly correlated multi-reference configuration interaction {it ab initio} calculations are done, and full dimensional potential energy surfaces are developed for the three lower electronic states, with a fundamental invariant neural network method. The photodissociation cross section is calculated using a full dimensional quantum wave packet method,Read More →

Confronting Dark Matter Capture Rate with Continuous Gravitational Wave Probe of Local Neutron Stars Pooja Bhattacharjee, Amit Dutta Banik arXiv:2404.15038v1 Announce Type: new Abstract: Continuous gravitational waves (CGWs) from various astrophysical sources are one of the many future probes of upcoming Gravitational Wave (GW) search missions. Neutron stars (NSs) with deformity are one of the leading sources of CGW emissions. In this work, for the first time, a novel attempt to estimate the dark matter (DM) capture rate is performed using CGW as the probe to the local NS population. Competitive bounds on DM capture from the local NS population are reported when compared withRead More →

Uncovering an Excess of X-ray Point Sources in the Halos of Virgo Late-type Galaxies Zhensong Hu, Meicun Hou, Zhiyuan Li arXiv:2404.15057v1 Announce Type: new Abstract: We present a systematic search for extraplanar X-ray point sources around 19 late-type, highly inclined disk galaxies residing in the Virgo cluster, based on archival Chandra observations reaching a source detection sensitivity of $Lrm(0.5- 8~keV)sim10^{38}rm~erg~s^{-1}$. Based on the cumulative source surface density distribution as a function of projected vertical distance from the disk mid-plane, we identify a statistically significant ($sim3.3sigma$) excess of $sim20$ X-ray sources within a projected vertical off-disk distance of $0.92′-2.5’$ ($sim4.4-12 mathrm{kpc}$), the presence of which cannotRead More →

Resolving Red Giant Winds with the Hubble Space Telescope Brian E. Wood, Graham M. Harper, Hans-Reinhard Mueller arXiv:2404.15086v1 Announce Type: new Abstract: We describe recent spectroscopic observations of red giant stars made by the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope, which have provided spatially resolved observations of the warm chromospheric winds that predominate for early K to mid-M giants. The H I Lyman-alpha lines of a set of 11 red giants observed with the STIS/E140M echelle grating are first analyzed to ascertain wind H I column densities and total wind mass-loss rates. The M giants have estimated mass-loss ratesRead More →

Vanilla Inflation Predicts Negative Running Jerome Martin, Christophe Ringeval, Vincent Vennin arXiv:2404.15089v1 Announce Type: new Abstract: We show that the simplest, and currently favoured, theoretical realizations of cosmic inflation yield a sharp prediction for the running of the spectral index $alpha_mathrm{S}$. Using latest cosmological data, we compute its marginalized posterior probability distribution over the space of nearly 300 models of single-field slow-roll inflation. The most probable value is $alpha_mathrm{S}=-6.3 times 10^{-4}$, lying within the $98%$ credible interval $-1.8 times 10^{-3}arXiv:2404.15089v1 Announce Type: new Abstract: We show that the simplest, and currently favoured, theoretical realizations of cosmic inflation yield a sharp prediction for the running ofRead More →

What can cosmic-ray knees reveal about source populations? Myrto Falalaki, Vasiliki Pavlidou arXiv:2404.15097v1 Announce Type: new Abstract: Cosmic ray (CR) knees (spectral steepenings) encode information on CR accelerator populations. We seek population features that imprint onto knee observables in a manner that is robust enough to be discernible even in the presence of significant systematics in CR data. In particular, we explore how diversity among population members could imprint on the knee phenomenology, under the assumption that a knee is due to a fixed-rigidity cutoff in the source spectra. We use a simple theoretical model for a population of CR accelerators. Each population member acceleratesRead More →

Life Cycle Assessment of the Athena X-ray Integral Field Unit Didier Barret (IRAP, France), Vincent Albouys (CNES, France), J"urgen Kn"odlseder (IRAP, France), Xavier Loizillon (Scalian, France), Matteo D’Andrea (IAPS, Italy), Florence Ardellier (APC, France), Simon Bandler (NASA, United States), Pieter Dieleman (SRON, Netherlands), Lionel Duband (CEA-SBT, France), Luc Dubbeldam (SRON, Netherlands), Claudio Macculi (IAPS, Italy), Eduardo Medinaceli (INAF, Italy), Francois Pajot (IRAP, France), Damien Pr^ele (APC, France), Laurent Ravera (IRAP, France), Tanguy Thibert (CSL, Belgium), Isabel Vera Trallero (INTA, Spain), Natalie Webb (IRAP, France) arXiv:2404.15122v1 Announce Type: new Abstract: The X-ray Integral Field Unit (X-IFU) is the high-resolution X-ray spectrometer to fly on board theRead More →

Signature of Particle Diffusion on the X-ray Spectra of the blazar Mkn 421 C. Baheeja, S. Sahayanathan, F. M. Rieger, C. D. Ravikumar arXiv:2404.15171v1 Announce Type: new Abstract: The curvature in blazar spectrum has the potential to understand the particle dynamics in jets. We performed a detailed analysis of simultaneous Swift-XRT (0.3-10 keV) and NuSTAR (3-79 keV)} observations of Mkn 421. Our analysis of NuSTAR observations alone reveals that, during periods of low flux, the hard X-ray spectra are best represented by a steep power-law with photon index reaching $sim$ 3. However, the spectrum exhibits significant curvature during its high flux states. To investigate this,Read More →

A Unified Treatment of Kepler Occurrence to Trace Planet Evolution II: The Radius Cliff Formed by Atmospheric Escape Anne Dattilo, Natalie M. Batalha arXiv:2404.15172v1 Announce Type: new Abstract: The Kepler mission enabled us to look at the intrinsic population of exoplanets within our galaxy. In period-radius space, the distribution of the intrinsic population of planets contains structure that can trace planet formation and evolution history. The most distinctive feature in period-radius space is the radius cliff, a steep drop-off in occurrence between $2.5-4$R$_oplus$ across all period ranges, separating the sub-Neptune population from the rarer Neptunes orbiting within 1 au. Following our earlier work to measureRead More →

The Sensitivity of NEO Surveyor to Low-Perihelion Asteroids Joseph R. Masiero, Yuna G. Kwon, Dar W. Dahlen, Frank J. Masci, Amy K. Mainzer arXiv:2404.15195v1 Announce Type: new Abstract: Asteroids with low orbital perihelion distances experience extreme heating from the Sun that can modify their surfaces and trigger non-typical activity mechanisms. These objects are generally difficult to observe from ground-based telescopes due to their frequent proximity to the Sun. The Near Earth Object Surveyor mission, however, will regularly survey down to Solar elongations of 45 degrees and is well-suited for the detection and characterization of low-perihelion asteroids. Here, we use the survey simulation software tools developedRead More →

Dark Radiation with Baryon Acoustic Oscillations from DESI 2024 and the $H_0$ tension Itamar J. Allali, Alessio Notari, Fabrizio Rompineve arXiv:2404.15220v1 Announce Type: new Abstract: We investigate the presence of extra relativistic degrees of freedom in the early Universe, contributing to the effective number of neutrinos $N_text{eff}$, as $Delta N_text{eff}equiv N_text{eff}-3.044geq 0$, in light of the recent measurements of Baryon Acoustic Oscillations (BAO) by the DESI collaboration. We analyze one-parameter extensions of the $Lambda$CDM model where dark radiation (DR) is free streaming or behaves as a perfect fluid, due to self-interactions. We report a significant relaxation of upper bounds on $Delta N_text{eff}$, with respect toRead More →