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Your search keyword '"Aleman, I."' showing total 2 results
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2 results on '"Aleman, I."'

1. ALMA detection of Masers and Dasars in the Hydrogen Recombination Lines of the Planetary Nebula Mz3

Author

Abraham, Z., Beaklini, P. P. B., Aleman, I., Sahai, R., Zijlstra, A., Akras, S., Gonçalves, D. R., and Ueta, T.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

The hydrogen recombination lines H30$\alpha$, H40$\alpha$, H42$\alpha$, H50$\beta$ and H57$\gamma$ and the underlying bremsstrahlung continuum emission were detected with ALMA in the bipolar nebula Mz3. The source was not spatially resolved, but the velocity profile of the H30$\alpha$ line shows clear indication of maser amplification, confirming previous reports of laser amplification in the far infrared H recombination lines observed with Herschel Space Observatory. Comparison between the flux densities of the H50$\beta$, H40$\alpha$ and H42$\alpha$ lines show overcooling, or darkness amplification by stimulated absorption (dasar effect) at the LSR velocity of about $-25$ km s$^{-1}$, which constrains the density of the absorbing region to about 10$^3$ cm$^{-3}$. The H30$\alpha$ line, on the other hand, presents maser lines at LSR velocities of $-69$ and $-98$ km s$^{-1}$, which indicates ionized gas with densities close to 10$^7$ cm$^{-3}$. Although the source of emission was not resolved, it was possible to find the central position of the images for each velocity interval, which resulted in a well defined position-velocity distribution., Comment: Accepted for publication in The Astrophysical Journal

Published
2024

2. A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk.

Author

Berné O, Habart E, Peeters E, Schroetter I, Canin A, Sidhu A, Chown R, Bron E, Haworth TJ, Klaassen P, Trahin B, Van De Putte D, Alarcón F, Zannese M, Abergel A, Bergin EA, Bernard-Salas J, Boersma C, Cami J, Cuadrado S, Dartois E, Dicken D, Elyajouri M, Fuente A, Goicoechea JR, Gordon KD, Issa L, Joblin C, Kannavou O, Khan B, Lacinbala O, Languignon D, Le Gal R, Maragkoudakis A, Meshaka R, Okada Y, Onaka T, Pasquini S, Pound MW, Robberto M, Röllig M, Schefter B, Schirmer T, Simmer T, Tabone B, Tielens AGGM, Vicente S, Wolfire MG, Aleman I, Allamandola L, Auchettl R, Baratta GA, Baruteau C, Bejaoui S, Bera PP, Black JH, Boulanger F, Bouwman J, Brandl B, Brechignac P, Brünken S, Buragohain M, Burkhardt A, Candian A, Cazaux S, Cernicharo J, Chabot M, Chakraborty S, Champion J, Colgan SWJ, Cooke IR, Coutens A, Cox NLJ, Demyk K, Meyer JD, Engrand C, Foschino S, García-Lario P, Gavilan L, Gerin M, Godard M, Gottlieb CA, Guillard P, Gusdorf A, Hartigan P, He J, Herbst E, Hornekaer L, Jäger C, Janot-Pacheco E, Kaufman M, Kemper F, Kendrew S, Kirsanova MS, Knight C, Kwok S, Labiano Á, Lai TS, Lee TJ, Lefloch B, Le Petit F, Li A, Linz H, Mackie CJ, Madden SC, Mascetti J, McGuire BA, Merino P, Micelotta ER, Morse JA, Mulas G, Neelamkodan N, Ohsawa R, Paladini R, Palumbo ME, Pathak A, Pendleton YJ, Petrignani A, Pino T, Puga E, Rangwala N, Rapacioli M, Ricca A, Roman-Duval J, Roueff E, Rouillé G, Salama F, Sales DA, Sandstrom K, Sarre P, Sciamma-O'Brien E, Sellgren K, Shannon MJ, Simonnin A, Shenoy SS, Teyssier D, Thomas RD, Togi A, Verstraete L, Witt AN, Wootten A, Ysard N, Zettergren H, Zhang Y, Zhang ZE, and Zhen J

Abstract

Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surfaces of protoplanetary disks around low-mass stars, which affects planet formation within the disks. We report James Webb Space Telescope and Atacama Large Millimeter Array observations of a FUV-irradiated protoplanetary disk in the Orion Nebula. Emission lines are detected from the PDR; modeling their kinematics and excitation allowed us to constrain the physical conditions within the gas. We quantified the mass-loss rate induced by the FUV irradiation and found that it is sufficient to remove gas from the disk in less than a million years. This is rapid enough to affect giant planet formation in the disk.

Published
2024
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