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Astronomers Will Get Gravitational Wave Alerts Within 30 Seconds Any event in the cosmos generates gravitational waves, the bigger the event, the more disturbance. Events where black holes and neutron stars collide can send out waves detectable here on Earth. It is possible that there can be an event in visible light when neutron stars collide so to take advantage of every opportunity an early warning is essential. The teams at LIGO-Virgo-KAGRA observatories are working on an alert system that will alert astronomers within 30 seconds fo a gravity wave event. If warning is early enough it may be possible to identify the source andRead More →

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Next Generation Ion Engines Will Be Extremely Powerful During the Space Race, scientists in both the United States and the Soviet Union investigated the concept of ion propulsion. Like many early Space Age proposals, the concept was originally explored by luminaries like Konstantin Tsiolkovsky and Hermann Oberth – two of the “forefathers of rocketry.” Since then, the technology has been validated repeatedly by missions like the Deep Space-1 (DS-1) technology demonstrator, the ESA’s Smart-1 lunar orbiter, JAXA’s Hayabusa and Hayabysa 2 satellites, and NASA’s Dawn mission. Looking to the future of space exploration, researchers at the NASA Glenn Research Center (GRC) have been busy developingRead More →

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Neutron Stars Could be Capturing Primordial Black Holes The Milky Way has a missing pulsar problem in its core. Astronomers have tried to explain this for years. One of the more interesting ideas comes from a team of astronomers in Europe and invokes dark matter, neutron stars, and primordial black holes (PBHs). Astronomer Roberto Caiozzo, of the International School for Advanced Studies in Trieste, Italy, led a group examining the missing pulsar problem. “We do not observe pulsars of any kind in this inner region (except for the magnetar PSR J1745-2900),” he wrote in an email. “This was thought to be due to technical limitations,Read More →

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Dark matter: A new experiment aims to turn the ghostly substance into actual light A ghost is haunting our universe. This has been known in astronomy and cosmology for decades. Observations suggest that about 85% of all the matter in the universe is mysterious and invisible. These two qualities are reflected in its name: dark matter. phys.org Go to SourceRead More →

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Researchers advance detection of gravitational waves to study collisions of neutron stars and black holes Researchers at the University of Minnesota Twin Cities College of Science and Engineering co-led a new study by an international team that will improve the detection of gravitational waves—ripples in space and time. phys.org Go to SourceRead More →

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Japan’s Lunar Lander Survives its Third Lunar Night Space travel and exploration was never going to be easy. Failures are sadly all too common but it’s wonderful to see missions exceed expectations. The Japanese Space Agency’s SLIM lunar lander was only supposed to survive a single day but it’s survived three brutal, harsh lunar nights and is still going. The temperatures plummet to -170C at night and the lander was never designed to operate into the night. Even sat upside down on the surface it’s still sending back pictures and data.  The Japanese agency’s lunar lander known as SLIM (Smart Lander for Investigating the Moon)Read More →

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Research investigates radio emission of the rotating radio transient RRAT J1854+0306 Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), Chinese astronomers have investigated radio emission from a rotating radio transient known as RRAT J1854+0306. Results of the study, published April 15 on the preprint server arXiv, shed more light on the properties of this transient. phys.org Go to SourceRead More →

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Cosmological constraints from weak lensing scattering transform using HSC Y1 data Sihao Cheng, Gabriela A. Marques, Daniela Grand’on, Leander Thiele, Masato Shirasaki, Brice M’enard, Jia Liu arXiv:2404.16085v1 Announce Type: new Abstract: As weak lensing surveys go deeper, there is an increasing need for reliable characterization of non-Gaussian structures at small angular scales. Here we present the first cosmological constraints with weak lensing scattering transform, a statistical estimator that combines efficiency, robustness, and interpretability. With the Hyper Suprime-Cam survey (HSC) year 1 data, we obtain $Omega_text{m}=0.29_{-0.03}^{+0.04}$, $S_8equiv sigma_8(Omega_text{m}/0.3)^{0.5}=0.83pm0.02$, and intrinsic alignment strength $A_text{IA}=1.0pm0.4$ through simulation-based forward modeling. Our constraints are consistent with those derived from Planck.Read More →

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Observational parameters of Blue Large-Amplitude Pulsators P. Pietrukowicz, M. Latour, I. Soszynski, F. Di Mille, P. Soto King, R. Angeloni, R. Poleski, A. Udalski, M. K. Szymanski, K. Ulaczyk, S. Kozlowski, J. Skowron, D. M. Skowron, P. Mroz, K. Rybicki, P. Iwanek, M. Wrona, M. Gromadzki arXiv:2404.16089v1 Announce Type: new Abstract: Blue Large-Amplitude Pulsators (BLAPs) are a recently discovered class of short-period pulsating variable stars. In this work, we present new information on these stars based on photometric and spectroscopic data obtained for known and new objects detected by the OGLE survey. BLAPs are evolved objects with pulsation periods in the range of 3–75 min,Read More →

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A dark standard siren measurement of the Hubble constant following LIGO/Virgo/KAGRA O4a C. R. Bom, V. Alfradique, A. Palmese, G. Teixeira, L. Santana-Silva, A. Santos, P. Darc arXiv:2404.16092v1 Announce Type: new Abstract: We present a new constraint on the Hubble constant ($H_0$) from the standard dark siren method using a sample of $5$ well-covered gravitational wave (GW) alerts reported during the first part of the fourth LIGO/Virgo/KAGRA observing runs in combination with standard dark sirens from the first three runs. Our methodology relies on the galaxy catalog method alone. We use the full probability density estimation of photometric redshifts derived by a deep learning methodRead More →

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Spinning solar jets explained through the interplay between plasma sheets and vortex columns Sahel Dey, Piyali Chatterjee, Robertus Erdelyi arXiv:2404.16096v1 Announce Type: new Abstract: Bunches of swaying and spinning plasma jets in the solar atmosphere – the spicules – exhibit a variety of complex dynamics that are clearly observed in the images of the solar limb. Utilizing three-dimensional radiative magnetohydrodynamics (rMHD) simulation data, we uncover another facet of a forest of spicules that turns out to be a manifestation of the two-dimensional plasma drapery, instead of one-dimensional conical spikes. This fluted morphology is observed in other contexts like molecular clouds, auroras, and coronal loops. Further,Read More →

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Dust beyond the torus: Revealing the mid-infrared heart of local Seyfert ESO 428-G14 with JWST/MIRI Houda Haidar, David J. Rosario, Almudena Alonso-Herrero, Miguel Pereira-Santaella, Ismael Garc’ia-Bernete, Stephanie Campbell, Sebastian F. H"onig, Cristina Ramos Almeida, Erin Hicks, Daniel Delaney, Richard Davies, Claudio Ricci, Chris M. Harrison, Mason Leist, Enrique Lopez-Rodriguez, Santiago Garcia-Burillo, Lulu Zhang, Chris Packham, Poshak Gandhi, Anelise Audibert, Enrica Bellocchi, Peter Boorman, Andrew Bunker, Franc{c}oise Combes, Tanio Diaz Santos, Fergus R. Donnan, Omaira Gonzalez Martin, Laura Hermosa Mu~noz, Matthaios Charidis, Alvaro Labiano, Nancy A. Levenson, Daniel May, Dimitra Rigopoulou, Alberto Rodriguez Ardila, T. Taro Shimizu, Marko Stalevski, Martin Ward arXiv:2404.16100v1 Announce Type: new Abstract:Read More →

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A Cepheid systematics-free test of $H_0$ to $lesssim2.5%$ accuracy using SH0ES photometry Doron Kushnir (WIS), Amir Sharon (WIS) arXiv:2404.16102v1 Announce Type: new Abstract: The recent SH0ES determination of the Hubble constant, $H_0=73.04pm1.04$ km/s/Mpc, deviates significantly by $approx5sigma$ from the textit{Planck} value, stimulating discussions on cosmological model extensions. To minimize statistical uncertainty and mitigate sensitivity to systematic errors in any single anchor distance determination, SH0ES combines Cepheids from various observations, including those from Type Ia supernova (SNe Ia) host galaxies, NGC 4258, and closer galaxies (MW, LMC, SMC, and M31), although this mixed sample may introduce unknown or subtle systematic errors due to comparing distant andRead More →

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Satellite group infall into the Milky Way: exploring the Crater-Leo case with new HST proper motions Mariana P. J’ulio, Marcel S. Pawlowski, Sangmo Tony Sohn, Salvatore Taibi, Roeland P. van der Marel, Stacy S. McGaugh arXiv:2404.16110v1 Announce Type: new Abstract: Context. Within $Lambda$ Cold Dark Matter ($Lambda$CDM) simulations, Milky Way-like galaxies accrete some of their satellite galaxies in groups of 3-5 members rather than individually. It was also suggested that this might be the reason behind the origin of satellite planes. Objects accreted in groups are expected to share similar specific total energy and angular momentum, and also identical orbital planes and directions. Aims. LookingRead More →

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Resonance of low-frequency electromagnetic and ion-sound modes in the solar wind I. Y. Vasko, F. S. Mozer, T. Bowen, J. Verniero, X. An, A. V. Artemyev, J. W. Bonnell, J. Halekas, I. V. Kuzichev arXiv:2404.16121v1 Announce Type: new Abstract: Parker Solar Probe measurements have recently shown that coherent fast magnetosonic and Alfv'{e}n ion-cyclotron waves are abundant in the solar wind and can be accompanied by higher-frequency electrostatic fluctuations. In this letter we reveal the nonlinear process capable of channelling the energy of low-frequency electromagnetic to higher-frequency electrostatic fluctuations observed aboard Parker Solar Probe. We present Hall-MHD simulations demonstrating that low-frequency electromagnetic fluctuations can resonate withRead More →

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Detectability of Surface Biosignatures for Directly-Imaged Rocky Exoplanets Schuyler R. Borges, Gabrielle G. Jones, Tyler D. Robinson arXiv:2404.16126v1 Announce Type: new Abstract: Modeling the detection of life has never been more opportune. With next generation space telescopes, like the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky exoplanets potentially similar to Earth. However, currently, few realistic planetary spectra containing surface biosignatures have been paired with direct imaging telescope instrument models. Therefore, we use a HWO instrument noise model to assess the detection of surface biosignatures affiliated with oxygenic, anoxygenic, and nonphotosynthetic extremophiles. We pair the HWO telescope model to aRead More →

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Primordial dust rings, hidden dust mass, and the first generation of planetesimals in gravitationally unstable protoplanetary disks Eduard I. Vorobyov (University of Vienna, Department of Astrophysics, Vienna, Austria, Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia), Aleksandr M. Skliarevskii (Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia), Manuel Guedel (Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia), Tamara Molyarova (Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia) arXiv:2404.16151v1 Announce Type: new Abstract: Aims. A new mechanism of dust accumulation and planetesimal formation in a gravitationally unstable disk with suppressed magnetorotational instability is studied and compared with the classical dead zone inRead More →

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Swift X-Ray and UV Observations of six Gaia Binaries supposedly containing a Neutron Star B. Sbarufatti, F. Coti Zelati, A. Marino, S. Mereghetti, N. Rea, A. Treves arXiv:2404.16170v1 Announce Type: new Abstract: Recent observations have led to the discovery of numerous optically selected binaries containing an undetected component with mass consistent with a compact object (neutron star or white dwarf). Using the the Neil Gehrels Swift Observatory we have carried out X-ray and UV observations of a small sample of these binaries. Four systems are wide (with orbital period P>300 d), and they were chosen because of their small distance (darXiv:2404.16170v1 Announce Type: new Abstract:Read More →

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Position dependent radiation fields near accretion disks Kara Smith, Daniel Proga, Randall Dannen, Sergei Dyda, Tim Waters arXiv:2404.16175v1 Announce Type: new Abstract: In disk wind models for active galactic nuclei (AGN) outflows, high-energy radiation poses a significant problem wherein the gas can become overionized, effectively disabling what is often inferred to be the largest force acting on the gas: the radiation force due to spectral line opacity. Calculations of this radiation force depend on the magnitude of ionizing radiation, which can strongly depend on the position above a disk where the radiation is anisotropic. As our first step to quantify the position and direction dependenceRead More →

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Unveiling very young O stars. Two Galactic O2V((f*))z in Westerlund 2 A. Roman-Lopes arXiv:2404.16178v1 Announce Type: new Abstract: O-type stars are known to significantly contribute to both the dynamics and evolution of galaxies. Massive and luminous, they probably control and regulate the galaxies star formation rates. For this work I performed a redetermination of the spectral types and effective temperatures of the Galactic O-type stars MSP182, MSP183, MSP199, VPHAS-01338, and VPHAS-01273. From a careful examination of the spectral features present in the blue optical spectral region, it was possible to identify several nitrogen lines usually only seen in the blue optical spectra of O2-O3 stars.Read More →