2006
DOI: 10.1086/506375
|View full text |Cite
|
Sign up to set email alerts
|

Abstract: We have carried out Very Large Array (VLA) continuum observations to study the variability of Sgr A Ã at 43 GHz (k ¼ 7 mm) and 22 GHz (k ¼ 13 mm). A low level of flare activity has been detected with a duration of $2 hr at these frequencies, showing the peak flare emission at 43 GHz leading the 22 GHz peak flare by $20-40 minutes. The overall characteristics of the flare emission are interpreted in terms of the plasmon model of van der Laan by considering the ejection and adiabatic expansion of a uniform, sphe… Show more

Help me understand this report
View preprint versions

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
1
1
1

Citation Types

30
202
0
2

Year Published

2010
2010
2022
2022

Publication Types

Select...
4
2
1

Relationship

1
6

Authors

Journals

citations
Cited by 161 publications
(234 citation statements)
references
References 43 publications
30
202
0
2
Order By: Relevance
“…Figure 4 then shows that this corresponds to a median densities of the order of 10 7.5 cm −3 , which compares well with density values in the literature (e.g. Yusef-Zadeh et al 2006a;Yuan et al 2003Yuan et al , 2004. However, for models with higher turnover frequencies, higher densities are required (see paramerization in Figs.…”
Section: Sub-mm Variability and Nir/x-ray Flaressupporting
confidence: 86%
See 2 more Smart Citations
“…Figure 4 then shows that this corresponds to a median densities of the order of 10 7.5 cm −3 , which compares well with density values in the literature (e.g. Yusef-Zadeh et al 2006a;Yuan et al 2003Yuan et al , 2004. However, for models with higher turnover frequencies, higher densities are required (see paramerization in Figs.…”
Section: Sub-mm Variability and Nir/x-ray Flaressupporting
confidence: 86%
“…In addition multi-wavelength observations of flares suggest an adiabatically expanding blob model (Eckart et al 2006a(Eckart et al , 2008Yusef-Zadeh et al 2006a, which can explain the observed time lags between the infrared/X-ray and millimeter flares. However, a general model that provides a quantitative explanation of the frequency-dependent variability of SgrA* in the millimeter and sub-millimeter wavelengths, including the contribution of thermal electrons and relativistic electrons that result in NIR/X-ray flares, is not yet available (see comments in Dexter et al 2010).…”
Section: Introductionmentioning
confidence: 91%
See 1 more Smart Citation
“…In this picture, the blob-like and arc-like structures noted in the east-west ridge of emission detected at radio wavelengths are interpreted to be expanding blobs produced by flaring activity escaping from Sgr A * . If the thermal density of expanding blobs is sufficient to overcome the external pressure, the outflow rate of thermal blobs of plasma is estimated to be 2×10 −8  M yr −1 (Yusef-Zadeh et al 2006). The expansion blob model has successfully been applied to flaring activity of microquasars where outflows have been detected (e.g., Fender & Belloni 2004).…”
Section: Flaring Activity Of Sgr a *mentioning
confidence: 99%
“…One is flaring on an hourly timescale at multiple wavelengths (e.g., Baganoff et al 2001;Genzel et al 2003). Observations of Sgr A * have detected a time delay at submillimeter, millimeter, and radio wavelengths consistent with a scenario in which plasma blobs expand away from the disk, becoming visible at successive longer wavelengths as the optical depths become of order unity effects (Yusef-Zadeh et al 2006Eckart et al 2008;Marrone et al 2008;Brinkerink et al 2015). The other is a jet-driven outflow (e.g., Falcke & Markoff 2000).…”
Section: Introductionmentioning
confidence: 96%