Zobrazeno 1 - 10
of 25
pro vyhledávání: '"Vedant Chandra"'
Autor:
Alexander P. Ji, Sanjana Curtis, Nicholas Storm, Vedant Chandra, Kevin C. Schlaufman, Keivan G. Stassun, Alexander Heger, Marco Pignatari, Adrian M. Price-Whelan, Maria Bergemann, Guy S. Stringfellow, Carla Fröhlich, Henrique Reggiani, Erika M. Holmbeck, Jamie Tayar, Shivani P. Shah, Emily J. Griffith, Chervin F. P. Laporte, Andrew R. Casey, Keith Hawkins, Danny Horta, William Cerny, Pierre Thibodeaux, Sam A. Usman, João A. S. Amarante, Rachael L. Beaton, Phillip A. Cargile, Cristina Chiappini, Charlie Conroy, Jennifer A. Johnson, Juna A. Kollmeier, Haining Li, Sarah Loebman, Georges Meynet, Dmitry Bizyaev, Joel R. Brownstein, Pramod Gupta, Sean Morrison, Kaike Pan, Solange V. Ramirez, Hans-Walter Rix, José Sánchez-Gallego
Publikováno v:
The Astrophysical Journal Letters, Vol 961, Iss 2, p L41 (2024)
Stars that formed with an initial mass of over 50 M _⊙ are very rare today, but they are thought to be more common in the early Universe. The fates of those early, metal-poor, massive stars are highly uncertain. Most are expected to directly collap
Externí odkaz:
https://doaj.org/article/cb019f1a53ca4e8bbf8ef53fff9533f7
Autor:
Gautham Adamane Pallathadka, Vedant Chandra, Nadia L. Zakamska, Hsiang-Chih Hwang, Yossef Zenati, J. J. Hermes, Kareem El-Badry, Boris T. Gänsicke, Sean Morrison, Nicole R. Crumpler, Stefan Arseneau
Publikováno v:
The Astrophysical Journal, Vol 968, Iss 1, p 42 (2024)
We report the discovery of SDSS J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive (>1 M _⊙ at 2 σ confidence) companion with a period of 36 hr. We use a combination of spectroscopy, including data from the
Externí odkaz:
https://doaj.org/article/62a13503445a400e8b6597480272c441
Publikováno v:
The Astrophysical Journal Supplement Series, Vol 272, Iss 1, p 2 (2024)
We present AspGap, a new approach to inferring stellar labels from the low-resolution Gaia XP spectra, including precise [ α /M] estimates—the first time these are obtained by such an approach. AspGap is a neural-network-based regression model tra
Externí odkaz:
https://doaj.org/article/9b576ab6d55b4fcf9e09d9c300f2ff52
Autor:
Logan Sizemore, Diego Llanes, Marina Kounkel, Brian Hutchinson, Keivan G. Stassun, Vedant Chandra
Publikováno v:
The Astronomical Journal, Vol 167, Iss 4, p 173 (2024)
Data-driven models, which apply machine learning to infer physical properties from large quantities of data, have become increasingly important for extracting stellar properties from spectra. In general, these methods have been applied to data in one
Externí odkaz:
https://doaj.org/article/936524515a284d16b0aa501b4dcc5bd0
Autor:
Stefan Arseneau, Vedant Chandra, Hsiang-Chih Hwang, Nadia L. Zakamska, Gautham Adamane Pallathadka, Nicole R. Crumpler, J. J. Hermes, Kareem El-Badry, Hans-Walter Rix, Keivan G. Stassun, Boris T. Gänsicke, Joel R. Brownstein, Sean Morrison
Publikováno v:
The Astrophysical Journal, Vol 963, Iss 1, p 17 (2024)
Measuring the mass–radius relation of individual white dwarfs is an empirically challenging task that has been performed for only a few dozen stars. We measure the white dwarf mass–radius relation using the gravitational redshifts and radii of 13
Externí odkaz:
https://doaj.org/article/15bbd847e35f4c6c9de1df2a48d4f385
Publikováno v:
The Astrophysical Journal, Vol 962, Iss 1, p 84 (2024)
Recent results from spectroscopic and astrometric surveys of nearby stars suggest that the stellar disk of our Milky Way (MW) was formed quite early, within the first few billion years of its evolution. Chemokinematic signatures of disk formation in
Externí odkaz:
https://doaj.org/article/9c887757eece48fdb9e8af6230afc792
Autor:
Kareem Jahaveri, Ken J. Shen, Vedant Chandra, Evan B. Bauer, Jim Fuller, Jay Strader, Laura Chomiuk, Rohan P. Naidu, Ilaria Caiazzo, Antonio C. Rodriguez, Pranav Nagarajan, Natsuko Yamaguchi, Zachary P. Vanderbosch, Benjamin R. Roulston, Boris Gänsicke, Jiwon Jesse Han, Kevin B. Burdge, Alexei V. Filippenko, Thomas G. Brink, WeiKang Zheng
Publikováno v:
The Open Journal of Astrophysics, Vol 6 (2023)
Externí odkaz:
https://doaj.org/article/3a521496ade9439597b13d70ed0c7e13
Autor:
Vedant Chandra, Rohan P. Naidu, Charlie Conroy, Ana Bonaca, Dennis Zaritsky, Phillip A. Cargile, Nelson Caldwell, Benjamin D. Johnson, Jiwon Jesse Han, Yuan-Sen Ting
Publikováno v:
The Astrophysical Journal, Vol 956, Iss 2, p 110 (2023)
The Magellanic Stream (MS)—an enormous ribbon of gas spanning 140° of the southern sky trailing the Magellanic Clouds—has been exquisitely mapped in the five decades since its discovery. However, despite concerted efforts, no stellar counterpart
Externí odkaz:
https://doaj.org/article/406065d4e6ee41a68acf40933f76729c
Autor:
Andrés Almeida, Scott F. Anderson, Maria Argudo-Fernández, Carles Badenes, Kat Barger, Jorge K. Barrera-Ballesteros, Chad F. Bender, Erika Benitez, Felipe Besser, Jonathan C. Bird, Dmitry Bizyaev, Michael R. Blanton, John Bochanski, Jo Bovy, William Nielsen Brandt, Joel R. Brownstein, Johannes Buchner, Esra Bulbul, Joseph N. Burchett, Mariana Cano Díaz, Joleen K. Carlberg, Andrew R. Casey, Vedant Chandra, Brian Cherinka, Cristina Chiappini, Abigail A. Coker, Johan Comparat, Charlie Conroy, Gabriella Contardo, Arlin Cortes, Kevin Covey, Jeffrey D. Crane, Katia Cunha, Collin Dabbieri, James W. Davidson Jr, Megan C. Davis, Anna Barbara de Andrade Queiroz, Nathan De Lee, José Eduardo Méndez Delgado, Sebastian Demasi, Francesco Di Mille, John Donor, Peter Dow, Tom Dwelly, Mike Eracleous, Jamey Eriksen, Xiaohui Fan, Emily Farr, Sara Frederick, Logan Fries, Peter Frinchaboy, Boris T. Gänsicke, Junqiang Ge, Consuelo González Ávila, Katie Grabowski, Catherine Grier, Guillaume Guiglion, Pramod Gupta, Patrick Hall, Keith Hawkins, Christian R. Hayes, J. J. Hermes, Lorena Hernández-García, David W. Hogg, Jon A. Holtzman, Hector Javier Ibarra-Medel, Alexander Ji, Paula Jofre, Jennifer A. Johnson, Amy M. Jones, Karen Kinemuchi, Matthias Kluge, Anton Koekemoer, Juna A. Kollmeier, Marina Kounkel, Dhanesh Krishnarao, Mirko Krumpe, Ivan Lacerna, Paulo Jakson Assuncao Lago, Chervin Laporte, Chao Liu, Ang Liu, Xin Liu, Alexandre Roman Lopes, Matin Macktoobian, Steven R. Majewski, Viktor Malanushenko, Dan Maoz, Thomas Masseron, Karen L. Masters, Gal Matijevic, Aidan McBride, Ilija Medan, Andrea Merloni, Sean Morrison, Natalie Myers, Szabolcs Mészáros, C. Alenka Negrete, David L. Nidever, Christian Nitschelm, Daniel Oravetz, Audrey Oravetz, Kaike Pan, Yingjie Peng, Marc H. Pinsonneault, Rick Pogge, Dan Qiu, Solange V. Ramirez, Hans-Walter Rix, Daniela Fernández Rosso, Jessie Runnoe, Mara Salvato, Sebastian F. Sanchez, Felipe A. Santana, Andrew Saydjari, Conor Sayres, Kevin C. Schlaufman, Donald P. Schneider, Axel Schwope, Javier Serna, Yue Shen, Jennifer Sobeck, Ying-Yi Song, Diogo Souto, Taylor Spoo, Keivan G. Stassun, Matthias Steinmetz, Ilya Straumit, Guy Stringfellow, José Sánchez-Gallego, Manuchehr Taghizadeh-Popp, Jamie Tayar, Ani Thakar, Patricia B. Tissera, Andrew Tkachenko, Hector Hernandez Toledo, Benny Trakhtenbrot, José G. Fernández-Trincado, Nicholas Troup, Jonathan R. Trump, Sarah Tuttle, Natalie Ulloa, Jose Antonio Vazquez-Mata, Pablo Vera Alfaro, Sandro Villanova, Stefanie Wachter, Anne-Marie Weijmans, Adam Wheeler, John Wilson, Leigh Wojno, Julien Wolf, Xiang-Xiang Xue, Jason E. Ybarra, Eleonora Zari, Gail Zasowski
Publikováno v:
The Astrophysical Journal Supplement Series, Vol 267, Iss 2, p 44 (2023)
The eighteenth data release (DR18) of the Sloan Digital Sky Survey (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs or “Mappers”: the Milky Way Mapper (MWM), the Black Hole
Externí odkaz:
https://doaj.org/article/c316293bd0cb4069bc0c64377b2d0cef
Publikováno v:
The Astrophysical Journal Supplement Series, Vol 267, Iss 1, p 8 (2023)
We derive and publish data-driven estimates of stellar metallicity [M/H] for ∼175 million stars with low-resolution XP spectra published in Gaia DR3. The [M/H] values, along with T _eff and $\mathrm{log}g$ , are derived using the XGBoost algorithm,
Externí odkaz:
https://doaj.org/article/cc8f1405a94e476da7208ce29132233b