Zobrazeno 1 - 10
of 16
pro vyhledávání: '"Yongda Zhu"'
Autor:
Danyang Jiang, Masafusa Onoue, Linhua Jiang, Samuel Lai, Eduardo Bañados, George D. Becker, Manuela Bischetti, Sarah E. I. Bosman, Rebecca L. Davies, Valentina D’Odorico, Emanuele Paolo Farina, Martin G. Haehnelt, Chiara Mazzucchelli, Jan-Torge Schindler, Fabian Walter, Yongda Zhu
Publikováno v:
The Astrophysical Journal, Vol 975, Iss 2, p 214 (2024)
The Fe ii /Mg ii emission line flux ratio in quasar spectra serves as a proxy for the relative Fe to α -element abundances in the broad-line regions of quasars. Due to the expected different enrichment timescales of the two elements, they can be use
Externí odkaz:
https://doaj.org/article/38c04e06a8c64767a25db98b5adba2eb
Autor:
Meredith A. Stone, Stacey Alberts, George H. Rieke, Andrew J. Bunker, Jianwei Lyu, Pablo G. Pérez-González, Irene Shivaei, Yongda Zhu
Publikováno v:
The Astrophysical Journal, Vol 972, Iss 1, p 62 (2024)
Galaxy number counts probe the evolution of galaxies over cosmic time and serve as a valuable comparison point to theoretical models of galaxy formation. We present new galaxy number counts in eight photometric bands between 5 and 25 μ m from the Sy
Externí odkaz:
https://doaj.org/article/d7dd2e4b5f394af096f5ab1cee1b3fed
Autor:
Manuela Bischetti, Hyunseop Choi, Fabrizio Fiore, Chiara Feruglio, Stefano Carniani, Valentina D’Odorico, Eduardo Bañados, Huanqing Chen, Roberto Decarli, Simona Gallerani, Julie Hlavacek-Larrondo, Samuel Lai, Karen M. Leighly, Chiara Mazzucchelli, Laurence Perreault-Levasseur, Roberta Tripodi, Fabian Walter, Feige Wang, Jinyi Yang, Maria Vittoria Zanchettin, Yongda Zhu
Publikováno v:
The Astrophysical Journal, Vol 970, Iss 1, p 9 (2024)
Although the mass growth of supermassive black holes during the epoch of reionization is expected to play a role in shaping the concurrent growth of their host galaxies, observational evidence of feedback at z ≳ 6 is still sparse. We perform the fi
Externí odkaz:
https://doaj.org/article/ba09e8dbe250469a871eb6016ab3502f
Autor:
Frederick B. Davies, Sarah E. I. Bosman, Prakash Gaikwad, Fahad Nasir, Joseph F. Hennawi, George D. Becker, Martin G. Haehnelt, Valentina D’Odorico, Manuela Bischetti, Anna-Christina Eilers, Laura C. Keating, Girish Kulkarni, Samuel Lai, Chiara Mazzucchelli, Yuxiang Qin, Sindhu Satyavolu, Feige Wang, Jinyi Yang, Yongda Zhu
Publikováno v:
The Astrophysical Journal, Vol 965, Iss 2, p 134 (2024)
The variations in Ly α forest opacity observed at z > 5.3 between lines of sight to different background quasars are too strong to be caused by fluctuations in the density field alone. The leading hypothesis for the cause of this excess variance is
Externí odkaz:
https://doaj.org/article/2b86c9a6a1ff452ab720479c96d8d968
Autor:
Holly M. Christenson, George D. Becker, Anson D’Aloisio, Frederick B. Davies, Yongda Zhu, Elisa Boera, Fahad Nasir, Steven R. Furlanetto, Matthew A. Malkan
Publikováno v:
The Astrophysical Journal, Vol 955, Iss 2, p 138 (2023)
Observed scatter in the Ly α opacity of quasar sightlines at z < 6 has motivated measurements of the correlation between Ly α opacity and galaxy density, as models that predict this scatter make strong and sometimes opposite predictions for how the
Externí odkaz:
https://doaj.org/article/1ce2152e03fa4cf189abf14eaf93d51d
Autor:
Yongda Zhu, George D. Becker, Holly M. Christenson, Anson D’Aloisio, Sarah E. I. Bosman, Tom Bakx, Valentina D’Odorico, Manuela Bischetti, Christopher Cain, Frederick B. Davies, Rebecca L. Davies, Anna-Christina Eilers, Xiaohui Fan, Prakash Gaikwad, Martin G. Haehnelt, Laura C. Keating, Girish Kulkarni, Samuel Lai, Hai-Xia Ma, Andrei Mesinger, Yuxiang Qin, Sindhu Satyavolu, Tsutomu T. Takeuchi, Hideki Umehata, Jinyi Yang
Publikováno v:
The Astrophysical Journal, Vol 955, Iss 2, p 115 (2023)
The mean free path of ionizing photons, λ _mfp , is a critical parameter for modeling the intergalactic medium (IGM) both during and after reionization. We present direct measurements of λ _mfp from QSO spectra over the redshift range 5 < z < 6, in
Externí odkaz:
https://doaj.org/article/598d97dba9064e05a6e4de4028082ba7
Autor:
Manuela Bischetti, Fabrizio Fiore, Chiara Feruglio, Valentina D’Odorico, Nahum Arav, Tiago Costa, Kastytis Zubovas, George Becker, Sarah E. I. Bosman, Guido Cupani, Rebecca Davies, Anna-Christina Eilers, Emanuele Paolo Farina, Andrea Ferrara, Massimo Gaspari, Chiara Mazzucchelli, Masafusa Onoue, Enrico Piconcelli, Maria Vittoria Zanchettin, Yongda Zhu
Publikováno v:
The Astrophysical Journal, Vol 952, Iss 1, p 44 (2023)
Luminous quasars are powerful targets to investigate the role of feedback from supermassive black holes (BHs) in regulating the growth phases of BHs themselves and of their host galaxies, up to the highest redshifts. Here we investigate the cosmic ev
Externí odkaz:
https://doaj.org/article/0d074c5a07794005bf4f31a30be39173
Autor:
Yongda Zhu, Hai-Xia Ma, Xiao-Bo Dong, Yang Huang, Tobias Mistele, Bo Peng, Qian Long, Tianqi Wang, Liang Chang, Xi Jin
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 519:4479-4498
Aiming at discriminating different gravitational potential models of the Milky Way, we perform tests based on the kinematic data powered by the Gaia DR2 astrometry, over a large range of $(R,z)$ locations. Invoking the complete form of Jeans equation
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8c2e0d0d4f397fefc30da82930bca2b6
https://doi.org/10.1093/mnras/stac3483
https://doi.org/10.1093/mnras/stac3483
Autor:
Yongda Zhu, George D. Becker, Sarah E. I. Bosman, Laura C. Keating, Valentina D’Odorico, Rebecca L. Davies, Holly M. Christenson, Eduardo Bañados, Fuyan Bian, Manuela Bischetti, Huanqing Chen, Frederick B. Davies, Anna-Christina Eilers, Xiaohui Fan, Prakash Gaikwad, Bradley Greig, Martin G. Haehnelt, Girish Kulkarni, Samuel Lai, Andrea Pallottini, Yuxiang Qin, Emma V. Ryan-Weber, Fabian Walter, Feige Wang, Jinyi Yang
We present a new investigation of the intergalactic medium (IGM) near reionization using dark gaps in the Lyman-$\beta$ (Ly$\beta$) forest. With its lower optical depth, Ly$\beta$ offers a potentially more sensitive probe to any remaining neutral gas
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fe76758a10d168c1c242d07a050f73d2
https://hdl.handle.net/11384/123443
https://hdl.handle.net/11384/123443
Autor:
Samuel Lai, Fuyan Bian, Christopher A Onken, Christian Wolf, Chiara Mazzucchelli, Eduardo Bañados, Manuela Bischetti, Sarah E I Bosman, George Becker, Guido Cupani, Valentina D’Odorico, Anna-Christina Eilers, Xiaohui Fan, Emanuele Paolo Farina, Masafusa Onoue, Jan-Torge Schindler, Fabian Walter, Feige Wang, Jinyi Yang, Yongda Zhu
Publikováno v:
Monthly Notices of the Royal Astronomical Society, 513(2), 1801-1819
The elemental abundances in the broad-line regions of high-redshift quasars trace the chemical evolution in the nuclear regions of massive galaxies in the early universe. In this work, we study metallicity-sensitive broad emission-line flux ratios in
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0551eca505fbc60a6b9e4f9d81833b92
https://academic.oup.com/mnras/article/513/2/1801/656634
https://academic.oup.com/mnras/article/513/2/1801/656634