Physical Sciences and Mathematics Commons^™

Satcon2: Community Engagement Working Group Report, Aparna Venkatesan, J. D. Lowenthal, Doug Arion, Fernando Avila Castro, Michele Bannister, John Barentine, David Begay, Juan-Carlos Chavez, Sally Carttar, Et Al

Astronomy: Faculty Publications

The SATCON2 Community Engagement Working Group aimed to engage a broad and diverse swath of stakeholders in dark skies and near-Earth space who are impacted by large mega-constellations of tens of thousands of low-Earth orbit (LEO) satellites, beyond professional astronomy alone. The working group consisted of 22 members across 23 time zones including professional and amateur astronomers, members of sovereign Indigenous/First Nations communities, dark-sky advocates, planetarium professionals, and environmental/ecological non-governmental organizations. We set out to work together towards a new and effective conceptual, ethical, legal, and regulatory framework for the protection and sustainability of space and the night sky as …

The Mass Of Β Pictoris C From Β Pictoris B Orbital Motion, S. Lacour, J. J. Wang, L. Rodet, M. Nowak, J. Shangguan, H. Beust, A. M. Lagrange, R. Abuter, A. Amorim, R. Asensio-Torres, M. Benisty, J. P. Berger, S. Blunt, A. Boccaletti, A. Bohn, M. L. Bolzer, M. Bonnefoy, H. Bonnet, G. Bourdarot, W. Brandner, F. Cantalloube, P. Caselli, B. Charnay, G. Chauvin, E. Choquet, V. Christiaens, Y. Clénet, V. Coudé Du Foresto, A. Cridland, R. Dembet, J. Dexter, P. T. De Zeeuw, K. Ward-Duong, Et Al

Astronomy: Faculty Publications

Aims. We aim to demonstrate that the presence and mass of an exoplanet can now be effectively derived from the astrometry of another exoplanet. Methods. We combined previous astrometry of β Pictoris b with a new set of observations from the GRAVITY interferometer. The orbital motion of β Pictoris b is fit using Markov chain Monte Carlo simulations in Jacobi coordinates. The inner planet, β Pictoris c, was also reobserved at a separation of 96 mas, confirming the previous orbital estimations. Results. From the astrometry of planet b only, we can (i) detect the presence of β Pictoris c and …

Gravity K-Band Spectroscopy Of Hd 206893 B, Jens Kammerer, S. Lacour, T. Stolker, P. Mollière, D. K. Sing, E. Nasedkin, Pierre Kervella, J. J. Wang, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

Context. Near-infrared interferometry has become a powerful tool for studying the orbital and atmospheric parameters of substellar companions.

Aims. We aim to reveal the nature of the reddest known substellar companion HD 206893 B by studying its near-infrared colors and spectral morphology and by investigating its orbital motion. Methods. We fit atmospheric models for giant planets and brown dwarfs and perform spectral retrievals with petitRADTRANS and ATMO on the observed GRAVITY, SPHERE, and GPI spectra of HD 206893 B. To recover its unusual spectral features, first and foremost its extremely red near-infrared color, we include additional extinction by high-altitude dust …

Constraining The Nature Of The Pds 70 Protoplanets With Vlti/Gravity, J. J. Wang, A. Vigan, S. Lacour, M. Nowak, T. Stolker, R. J. De Rosa, S. Ginzburg, P. Gao, R. Abuter, A. Amorim, R. Asensio-Torres, M. Bauböck, M. Benisty, J. P. Berger, H. Beust, J. L. Beuzit, S. Blunt, A. Boccaletti, A. Bohn, M. Bonnefoy, H. Bonnet, W. Brandner, F. Cantalloube, P. Caselli, B. Charnay, G. Chauvin, E. Choquet, V. Christiaens, Y. Clénet, V. Coudé Du Foresto, A. Cridland, P. T. De Zeeuw, K. Ward-Duong, Et Al

Astronomy: Faculty Publications

We present K-band interferometric observations of the PDS 70 protoplanets along with their host star using VLTI/ GRAVITY. We obtained K-band spectra and 100 μas precision astrometry of both PDS 70 b and c in two epochs, as well as spatially resolving the hot inner disk around the star. Rejecting unstable orbits, we found a nonzero eccentricity for PDS 70 b of 0.17 ± 0.06, a near-circular orbit for PDS 70 c, and an orbital configuration that is consistent with the planets migrating into a 2:1 mean motion resonance. Enforcing dynamical stability, we obtained a 95% upper limit on the …

Turbulent Gas In Lensed Planck-Selected Starbursts At Z ∼ 1-3.5, Kevin C. Harrington, Axel Weiss, Min S. Yun, Benjamin Magnelli, C. E. Sharon, T. K.D. Leung, A. Vishwas, Q. D. Wang, D. T. Frayer, E. F. Jiménez-Andrade, D. Liu, P. García, E. Romano-Díaz, B. L. Frye, S. Jarugula, T. Bǎdescu, D. Berman, H. Dannerbauer, A. Díaz-Sánchez, L. Grassitelli, P. Kamieneski, W. J. Kim, A. Kirkpatrick, J. D. Lowenthal, H. Messias, J. Puschnig, G. J. Stacey, P. Torne, F. Bertoldi

Astronomy: Faculty Publications

Dusty star-forming galaxies at high redshift (1 < z < 3) represent the most intense star-forming regions in the universe. Key aspects to these processes are the gas heating and cooling mechanisms, and although it is well known that these galaxies are gas-rich, little is known about the gas excitation conditions. Only a few detailed radiative transfer studies have been carried out owing to a lack of multiple line detections per galaxy. Here we examine these processes in a sample of 24 strongly lensed star-forming galaxies identified by the Planck satellite (LPs) at z ∼ 1.1-3.5. We analyze 162 CO rotational transitions (ranging from J up = 1 to 12) and 37 atomic carbon fine-structure lines ([C i]) in order to characterize the physical conditions of the gas in the sample of LPs. We simultaneously fit the CO and [C i] lines and the dust continuum emission, using two different non-LTE, radiative transfer models. The first model represents a two-component gas density, while the second assumes a turbulence-driven lognormal gas density distribution. These LPs are among the most gas-rich, IR-luminous galaxies ever observed (μL L IR(8-1000 μm) ∼ 1013-14.6 L⊙; «μLMISM» = (2.7 ± 1.2) × 1012 Mo˙ with μL ∼ 10-30 the average lens magnification factor). Our results suggest that the turbulent interstellar medium present in the LPs can be well characterized by a high turbulent velocity dispersion («ΔVturb» ∼ 100 km s-1) and ratios of gas kinetic temperature to dust temperature «T kin/T d» ∼ 2.5, sustained on scales larger than a few kiloparsecs. We speculate that the average surface density of the molecular gas mass and IR luminosity, Σ ∼ 103-4 M o˙ pc-2 and Σ ∼ 1011-12 L o˙ kpc-2, arise from both stellar mechanical feedback and a steady momentum injection from the accretion of intergalactic gas.

Gemini Planet Imager Spectroscopy Of The Dusty Substellar Companion Hd 206893 B, Kimberly Ward-Duong, J. Patience, K. Follette, R. J.De Rosa, J. Rameau, M. Marley, D. Saumon, E. L. Nielsen, A. Rajan, A. Z. Greenbaum, J. Lee, J. J. Wang, I. Czekala, G. Duch Ne, B. Macintosh, S. Mark Ammons, V. P. Bailey, T. Barman, J. Bulger, C. Chen, J. Chilcote, T. Cotten, R. Doyon, T. M. Esposito, M. P. Fitzgerald, B. L. Gerard, S. J. Goodsell, J. R. Graham, P. Hibon, J. Hom, L. W. Hung, P. Ingraham

Astronomy: Faculty Publications

We present new near-infrared Gemini Planet Imager (GPI) spectroscopy of HD 206893 B, a substellar companion orbiting within the debris disk of its F5V star. The J, H, K1, and K2 spectra from GPI demonstrate the extraordinarily red colors of the object, confirming it as the reddest substellar object observed to date. The significant flux increase throughout the infrared presents a challenging atmosphere to model with existing grids. Best-fit values vary from 1200 to 1800 K for effective temperature and from 3.0 to 5.0 for log(g), depending on which individual wavelength band is fit and which model suite is applied. …