Search Publications
Deep Potential: Recovering the Gravitational Potential from a Snapshot of Phase Space
Ting, Yuan-Sen; Green, Gregory M.; Kamdar, Harshil
One of the major goals of the field of Milky Way dynamics is to recover the gravitational potential field. Mapping the potential would allow us to determine the spatial distribution of matter-both baryonic and dark-throughout the galaxy. We present a novel method for determining the gravitational field from a snapshot of the phase-space positions …
PHANGS-JWST First Results: A Combined HST and JWST Analysis of the Nuclear Star Cluster in NGC 628
Sandstrom, Karin M.; Neumayer, Nadine; Kruijssen, J. M. Diederik +28 more
We combine archival Hubble Space Telescope and new James Webb Space Telescope imaging data covering the ultraviolet to mid-infrared regime to morphologically analyze the nuclear star cluster (NSC) of NGC 628, a grand-design spiral galaxy. The cluster is located in a 200 pc × 400 pc cavity lacking both dust and gas. We find roughly constant values …
Empirical Measurement of the Dynamical Ages of Three Globular Clusters and Some Considerations on the Use of the Dynamical Clock
Vesperini, Enrico; Cadelano, Mario; Pallanca, Cristina +3 more
We have used the "dynamical clock" to measure the level of dynamical evolution reached by three Galactic globular clusters (namely, NGC 3201, NGC 6316, and NGC 6440). This is an empirical method that quantifies the level of central segregation of blue straggler stars (BSSs) within the cluster half-mass radius by means of the ${A}_{\mathrm{rh}}^{+}…
Primordial or Secondary? Testing Models of Debris Disk Gas with ALMA
Henning, Thomas; Hughes, A. Meredith; Redfield, Seth +13 more
The origin and evolution of gas in debris disks are still not well understood. Secondary gas production from cometary material or a primordial origin have been proposed. So far, observations have mostly concentrated on CO, with only a few C observations available. We overview the C and CO content of debris disk gas and test state-of-the-art models…
The Optical to Infrared Extinction Law of Magellanic Clouds Based on Red Supergiants and Classical Cepheids
Wang, Shu; Chen, Xiaodian
Precise interstellar dust extinction laws are important to infer the intrinsic properties of reddened objects and correctly interpret observations. In this work, we attempt to measure the optical-infrared extinction laws of the Large and Small Magellanic Clouds (LMC and SMC) by using red supergiant (RSG) stars and classical Cepheids as extinction …
Deciphering the Slow-rise Precursor of a Major Coronal Mass Ejection
Peter, H.; Solanki, S. K.; Aulanier, G. +3 more
Coronal mass ejections are explosive plasma phenomena prevalently occurring on the Sun and probably on other magnetically active stars. However, how their pre-eruptive configuration evolves toward the main explosion remains elusive. Here, based on comprehensive observations of a long-duration precursor in an event on 2012 March 13, we determine th…
Numerical Study on Excitation of Turbulence and Oscillation in Above-the-loop-top Region of a Solar Flare
Reeves, Katharine K.; Takasao, Shinsuke; Shibata, Kengo
Extreme-ultraviolet imaging spectroscopic observations often show an increase in line width around the loop-top or above-the-loop-top (ALT) region of solar flares, suggestive of turbulence. In addition, recent spectroscopic observations found the oscillation in the Doppler velocity around the ALT region. We performed 3D magnetohydrodynamic (MHD) s…
The Aligned Orbit of the Eccentric Proto Hot Jupiter TOI-3362b
Jordán, Andrés; Brahm, Rafael; Hobson, Melissa J. +8 more
High-eccentricity tidal migration predicts the existence of highly eccentric proto hot Jupiters on the "tidal circularization track," meaning that they might eventually become hot Jupiters, but that their migratory journey remains incomplete. Having experienced moderate amounts of tidal evolution of their orbital elements, proto hot Jupiter system…
J0107a: A Barred Spiral Dusty Star-forming Galaxy at z = 2.467
Tamura, Yoichi; Kohno, Kotaro; Iono, Daisuke +7 more
Dusty star-forming galaxies (DSFGs) are among the most massive and active star-forming galaxies during the cosmic noon. Theoretical studies have proposed various formation mechanisms of DSFGs, including major merger-driven starbursts and secular star-forming disks. Here, we report J0107a, a bright (~8 mJy at observed-frame 888 µm) DSFG at z …
Deep Spitzer/IRAC Data for z 10 Galaxies Reveal Blue Balmer Break Colors: Young Stellar Populations at 500 Myr of Cosmic Time
Illingworth, Garth D.; Labbé, Ivo; Bouwens, Rychard J. +3 more
We present the deepest constraints yet on the median rest-UV+optical spectral energy distribution (SED) of z ~ 10 galaxies prior to James Webb Space Telescope science operations. We constructed stacks based on four robust J 125 dropouts, previously identified across the GOODS fields. We used archival Hubble Space Telescope/Wide Field Ca…