Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/29400
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Boyce, H. | en_US |
dc.contributor.author | Haggard, D. | en_US |
dc.contributor.author | Witzel, G. | en_US |
dc.contributor.author | Willner, S. P. | en_US |
dc.contributor.author | Neilsen, J. | en_US |
dc.contributor.author | Hora, J. L. | en_US |
dc.contributor.author | Markoff, S. | en_US |
dc.contributor.author | PONTI, GABRIELE | en_US |
dc.contributor.author | Baganoff, F. | en_US |
dc.contributor.author | Becklin, E. E. | en_US |
dc.contributor.author | Fazio, G. G. | en_US |
dc.contributor.author | Lowrance, P. | en_US |
dc.contributor.author | Morris, M. R. | en_US |
dc.contributor.author | Smith, H. A. | en_US |
dc.date.accessioned | 2020-12-30T17:04:29Z | - |
dc.date.available | 2020-12-30T17:04:29Z | - |
dc.date.issued | 2019 | en_US |
dc.identifier.issn | 0004-637X | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/29400 | - |
dc.description.abstract | Emission from Saggitarius A* is highly variable at both X-ray and infrared (IR) wavelengths. Observations over the last ∼20 yr have revealed X-ray flares that rise above a quiescent thermal background about once per day, while faint X-ray flares from Sgr A* are undetectable below the constant thermal emission. In contrast, the IR emission of Sgr A* is observed to be continuously variable. Recently, simultaneous observations have indicated a rise in IR flux density around the same time as every distinct X-ray flare, while the opposite is not always true (peaks in the IR emission may not be coincident with an X-ray flare). Characterizing the behavior of these simultaneous X-ray/IR events and measuring any time lag between them can constrain models of Sgr A*'s accretion flow and the flare emission mechanism. Using 100+ hours of data from a coordinated campaign between the Spitzer Space Telescope and the Chandra X-ray Observatory, we present results of the longest simultaneous IR and X-ray observations of Sgr A* taken to date. The cross-correlation between the IR and X-ray light curves in this unprecedented data set, which includes four modest X-ray/IR flares, indicates that flaring in the X-ray may lead the IR by approximately 10-20 min with 68% confidence. However, the 99.7% confidence interval on the time-lag also includes zero, i.e., the flaring remains statistically consistent with simultaneity. Long-duration and simultaneous multi-wavelength observations of additional bright flares will improve our ability to constrain the flare timing characteristics and emission mechanisms, and must be a priority for Galactic Center observing campaigns. | en_US |
dc.language.iso | eng | en_US |
dc.title | Simultaneous X-Ray and Infrared Observations of Sagittarius A*'s Variability | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.3847/1538-4357/aaf71f | en_US |
dc.identifier.scopus | 2-s2.0-85062035786 | en_US |
dc.identifier.isi | 000457181200015 | en_US |
dc.identifier.url | https://iopscience.iop.org/article/10.3847/1538-4357/aaf71f | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 871 | en_US |
dc.relation.issue | 2 | en_US |
dc.relation.firstpage | 161 | en_US |
dc.type.referee | REF_1 | en_US |
dc.relation.scientificsector | FIS/05 - ASTRONOMIA E ASTROFISICA | en_US |
dc.relation.journal | THE ASTROPHYSICAL JOURNAL | en_US |
dc.type.miur | 262 Articolo in rivista | - |
dc.identifier.adsbibcode | 2019ApJ...871..161B | en_US |
dc.description.apc | no | en_US |
dc.description.oa | 1 – prodotto con file in versione Open Access (allegare il file al passo 5-Carica) | en_US |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.openairetype | Article | - |
item.languageiso639-1 | en | - |
item.cerifentitytype | Publications | - |
item.grantfulltext | open | - |
item.fulltext | With Fulltext | - |
crisitem.author.dept | O.A. Brera | - |
crisitem.author.orcid | 0000-0003-0293-3608 | - |
crisitem.journal.journalissn | 0004-637X | - |
crisitem.journal.ance | E016252 | - |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
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Boyce_2019_ApJ_871_161.pdf | pdf editoriale | 2.44 MB | Adobe PDF | View/Open |
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