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A population of dust-enshrouded objects orbiting the Galactic black hole 期刊论文
NATURE, 2020, 577 (7790) : 337-+
作者:  Witze, Alexandra
收藏  |  浏览/下载:8/0  |  提交时间:2020/07/03

The central 0.1 parsecs of the Milky Way host a supermassive black hole identified with the position of the radio and infrared source Sagittarius A* (refs.(1,2)), a cluster of young, massive stars (the S stars3) and various gaseous features(4,5). Recently, two unusual objects have been found to be closely orbiting Sagittarius A*: the so-called G sources, G1 and G2. These objects are unresolved (having a size of the order of 100 astronomical units, except at periapse, where the tidal interaction with the black hole stretches them along the orbit) and they show both thermal dust emission and line emission from ionized gas(6-10). G1 and G2 have generated attention because they appear to be tidally interacting with the supermassive Galactic black hole, possibly enhancing its accretion activity. No broad consensus has yet been reached concerning their nature: the G objects show the characteristics of gas and dust clouds but display the dynamical properties of stellar-mass objects. Here we report observations of four additional G objects, all lying within 0.04 parsecs of the black hole and forming a class that is probably unique to this environment. The widely varying orbits derived for the six G objects demonstrate that they were commonly but separately formed.


  
Forty years of ice-core records of CO2 期刊论文
NATURE, 2020, 579 (7800) : 505-506
作者:  Witze, Alexandra;  Watkins, Jessica
收藏  |  浏览/下载:8/0  |  提交时间:2020/07/03
Fast peer review for COVID-19 preprints 期刊论文
NATURE, 2020, 579 (7797) : 29-29
作者:  Witze, Alexandra
收藏  |  浏览/下载:8/0  |  提交时间:2020/07/03
How the fight over a Hawaii mega-telescope could change astronomy 期刊论文
NATURE, 2020, 577 (7791) : 457-458
作者:  Witze, Alexandra
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/03

Thirty Meter Telescope controversy is forcing scientists to grapple with how their research affects Indigenous peoples.


Thirty Meter Telescope controversy is forcing scientists to grapple with how their research affects Indigenous peoples.


  
How sewage could reveal true scale of coronavirus outbreak 期刊论文
NATURE, 2020, 580 (7802) : 176-177
作者:  Witze, Alexandra
收藏  |  浏览/下载:9/0  |  提交时间:2020/07/03

Wastewater testing could also be used as an early-warning sign if the virus returns.


Wastewater testing could also be used as an early-warning sign if the virus returns.


  
EARTH SCIENTISTS PUSH PLAN TO MAP CANADA'S GEOLOGY 期刊论文
NATURE, 2019, 574 (7779) : 463-464
作者:  Witze, Alexandra
收藏  |  浏览/下载:5/0  |  提交时间:2019/11/27
Scientists join climate strikes 期刊论文
NATURE, 2019, 573 (7775) : 472-473
作者:  Schiermeier, Quirin;  Atkinson, Kate;  Mega, Emiliano Rodriguez;  Padma, T. V.;  Stoye, Emma;  Tollefson, Jeff;  Witze, Alexandra
收藏  |  浏览/下载:9/0  |  提交时间:2019/11/27
NASA narrows sites for rock-harvesting Mars rover 期刊论文
NATURE, 2017, 542 (7641) : 279-+
作者:  Witze, Alexandra
收藏  |  浏览/下载:4/0  |  提交时间:2019/11/27
United States revives space-policy council after 24-year absence 期刊论文
NATURE, 2017, 546 (7658) : 337-337
作者:  Witze, Alexandra
收藏  |  浏览/下载:6/0  |  提交时间:2019/11/27
The weather observers on climate change's front lines 期刊论文
NATURE, 2019, 573 (7774) : 317-318
作者:  Witze, Alexandra
收藏  |  浏览/下载:1/0  |  提交时间:2019/11/27