Astrophysics – Page 2 – Kavli Institute Pre-Print Publications

Uniting the Observed Dynamical Dark Energy Preference with the Discrepancies in $Ω_m$ and $H_0$ Across Cosmological Probes

Posted by dbos Chicago, This Week: Astrophysics

Kavli Affiliate: Chihway Chang | First 5 Authors: Xianzhe TZ Tang, Dillon Brout, Tanvi Karwal, Chihway Chang, Vivian Miranda | Summary: Recent results from Type Ia Supernovae (SNe), baryon acoustic oscillations (BAO), and the cosmic microwave background (CMB) indicate 1) potentially discrepant measurements of the matter density $Omega_m$ and Hubble constant $ H_0 $ in […]

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Targeting the Core: A Simple and Effective Method to Attack RAG-based Agents via Direct LLM Manipulation

Posted by dbos December 5, 2024December 9, 2024Peking, This Week: Astrophysics

Kavli Affiliate: Zhuo Li | First 5 Authors: Xuying Li, Zhuo Li, Yuji Kosuga, Yasuhiro Yoshida, Victor Bian | Summary: AI agents, powered by large language models (LLMs), have transformed human-computer interactions by enabling seamless, natural, and context-aware communication. While these advancements offer immense utility, they also inherit and amplify inherent safety risks such as […]

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LossAgent: Towards Any Optimization Objectives for Image Processing with LLM Agents

Posted by dbos December 5, 2024December 9, 2024Peking, This Week: Astrophysics

Kavli Affiliate: Li Xin Li | First 5 Authors: Bingchen Li, Xin Li, Yiting Lu, Zhibo Chen, | Summary: We present the first loss agent, dubbed LossAgent, for low-level image processing tasks, e.g., image super-resolution and restoration, intending to achieve any customized optimization objectives of low-level image processing in different practical applications. Notably, not all […]

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Predictions of Dust Continuum Emission from a Potential Circumplanetary Disk: A Case Study of the Planet Candidate AB Aurigae b

Posted by dbos December 5, 2024December 9, 2024Peking, This Week: Astrophysics

Kavli Affiliate: Ruobing Dong | First 5 Authors: Yuhito Shibaike, Jun Hashimoto, Ruobing Dong, Christoph Mordasini, Misato Fukagawa | Summary: Gas accreting planets embedded in protoplanetary disks are expected to show dust thermal emission from their circumplanetary disks (CPDs). However, a recently reported gas accreting planet candidate, AB Aurigae b, has not been detected in […]

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JWST-TST DREAMS: A Precise Water Abundance for Hot Jupiter WASP-17b from the NIRISS SOSS Transmission Spectrum

Posted by dbos December 4, 2024December 9, 2024MIT, This Week: Astrophysics

Kavli Affiliate: Sara Seager | First 5 Authors: Dana R. Louie, Elijah Mullens, Lili Alderson, Ana Glidden, Nikole K. Lewis | Summary: Water has proven to be ubiquitously detected in near-infrared (NIR) transmission spectroscopy observations of hot Jupiter atmospheres, including WASP-17b. However, previous analyses of WASP-17b’s atmosphere based upon Hubble Space Telescope (HST) and Spitzer […]

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Weakness of X-rays and Variability in High-redshift AGNs with Super-Eddington Accretion

Posted by dbos December 4, 2024December 9, 2024Peking, This Week: Astrophysics

Kavli Affiliate: Kohei Inayoshi | First 5 Authors: Kohei Inayoshi, Shigeo Kimura, Hirofumi Noda, , | Summary: The James Webb Space Telescope (JWST) observations enable the exploration of active galactic nuclei (AGNs) with broad-line emission in the early universe. Despite their clear radiative and morphological signatures of AGNs in rest-frame optical bands, complementary evidence of […]

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A High Incidence of Central Star Formation Inferred from the Color Gradients of Galaxies at $z>4$

Posted by dbos December 4, 2024December 9, 2024Peking, This Week: Astrophysics

Kavli Affiliate: Luis C. Ho | First 5 Authors: Bingcheng Jin, Luis C. Ho, Wen Sun, , | Summary: We study the rest-frame ultraviolet-optical color gradients of 669 galaxies at $4<z<8$ by characterizing the wavelength dependence of their structural parameters derived from simultaneously fitting the seven-band NIRCam images acquired with the James Webb Space Telescope. […]

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An Image Simulator of Lunar Far-Side Impact Flashes Captured from the Earth-Moon L2 Point

Posted by dbos December 4, 2024December 9, 2024Peking, This Week: Astrophysics

Kavli Affiliate: Jing Wang | First 5 Authors: Da Song, Hong-bo Cai, Shen Wang, Jing Wang, | Summary: Impact flashes on the moon are caused by high-speed collisions of celestial bodies with the lunar surface. The study of the impacts is critical for exploring the evolutionary history and formation of the Moon, and for quantifying […]

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A Lower Mass Estimate for PSR J0348+0432 Based on CHIME/Pulsar Precision Timing

Posted by dbos December 3, 2024December 9, 2024MIT, This Week: Astrophysics

Kavli Affiliate: Kiyoshi W. Masui | First 5 Authors: Alexander Saffer, Emmanuel Fonseca, Scott Ransom, Ingrid Stairs, Ryan Lynch | Summary: The binary pulsar J0348+0432 was previously shown to have a mass of approximately 2,${rm M_odot}$, based on the combination of radial-velocity and model-dependent mass parameters derived from high-resolution optical spectroscopy of its white-dwarf companion. […]

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Discovery and Characterization of an Eccentric, Warm Saturn Transiting the Solar Analog TOI-4994

Posted by dbos December 3, 2024December 9, 2024MIT, This Week: Astrophysics

Kavli Affiliate: Sara Seager | First 5 Authors: Romy Rodriguez Martinez, Jason D. Eastman, Karen Collins, Joseph Rodriguez, David Charbonneau | Summary: We present the detection and characterization of TOI-4994b (TIC 277128619b), a warm Saturn-sized planet discovered by the NASA Transiting Exoplanet Survey Satellite (TESS). TOI-4994b transits a G-type star (V = 12.6 mag) with […]

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