scholarly journals A POWER-LAW BREAK IN THE NEAR-INFRARED POWER SPECTRUM OF THE GALACTIC CENTER BLACK HOLE

2009 ◽  
Vol 694 (1) ◽  
pp. L87-L91 ◽  
Author(s):  
L. Meyer ◽  
T. Do ◽  
A. Ghez ◽  
M. R. Morris ◽  
S. Yelda ◽  
...  
Keyword(s):  
Black Hole ◽  
Power Spectrum ◽  
Power Law ◽  
Near Infrared ◽  
Galactic Center

Clarification of the formation process of the super massive black hole by Infrared astrometric satellite, Small-JASMINE

2017 ◽  
Vol 12 (S330) ◽  
pp. 360-361 ◽  
Author(s):  
Taihei Yano ◽  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Phase Space ◽  
Formation Process ◽  
Near Infrared ◽  
Galactic Center ◽  
Space Distribution ◽  
Massive Black Hole ◽  
Phase Space Distribution ◽  
Merging Process

AbstractSmall-JASMINE (hearafter SJ), infrared astrometric satellite, will measure the positions and the proper motions which are located around the Galactic center, by operating at near infrared wave-lengths. SJ will clarify the formation process of the super massive black hole (hearafter SMBH) at the Galactic center. In particular, SJ will determine whether the SMBH was formed by a sequential merging of multiple black holes. The clarification of this formation process of the SMBH will contribute to a better understanding of merging process of satellite galaxies into the Galaxy, which is suggested by the standard galaxy formation scenario. A numerical simulation (Tanikawa and Umemura, 2014) suggests that if the SMBH was formed by the merging process, then the dynamical friction caused by the black holes have influenced the phase space distribution of stars. The phase space distribution measured by SJ will make it possible to determine the occurrences of the merging process.

scholarly journals GRAVITY: microarcsecond astrometry and deep interferometric imaging with the VLTI

2007 ◽  
Vol 3 (S248) ◽  
pp. 100-101 ◽  
Author(s):  
F. Eisenhauer ◽  
G. Perrin ◽  
C. Straubmeier ◽  
W. Brandner ◽  
A. Boehm ◽  
...  
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Galactic Center ◽  
Interferometric Imaging ◽  
Wavefront Sensors ◽  
Narrow Angle ◽  
Interferometric Phase ◽  
Wide Range

AbstractWe present the adaptive optics assisted, near-infrared VLTI instrument GRAVITY for precision narrow-angle astrometry and interferometric phase referenced imaging of faint objects. With its two fibers per telescope beam, its internal wavefront sensors and fringe tracker, and a novel metrology concept, GRAVITY will not only push the sensitivity far beyond what is offered today, but will also advance the astrometric accuracy for UTs to 10 μas. GRAVITY is designed to work with four telescopes, thus providing phase referenced imaging and astrometry for 6 baselines simultaneously. Its unique capabilities and sensitivity will open a new window for the observation of a wide range of objects, and — amongst others — will allow the study of motion within a few times the event horizon size of the Galactic Center black hole.

scholarly journals EXTENDED SUBMILLIMETER EMISSION OF THE GALACTIC CENTER AND NEAR-INFRARED/SUBMILLIMETER VARIABILITY OF ITS SUPERMASSIVE BLACK HOLE

2011 ◽  
Vol 738 (2) ◽  
pp. 158 ◽  
Author(s):  
M. García-Marín ◽  
A. Eckart ◽  
A. Weiss ◽  
G. Witzel ◽  
M. Bremer ◽  
...  
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Galactic Center ◽  
Supermassive Black Hole ◽  
Submillimeter Emission

scholarly journals 15 years of high precision astrometry in the Galactic Center

2007 ◽  
Vol 3 (S248) ◽  
pp. 466-469
Author(s):  
S. Gillessen ◽  
R. Genzel ◽  
F. Eisenhauer ◽  
T. Ott ◽  
S. Trippe ◽  
...  
Keyword(s):  
Black Hole ◽  
Mass Distribution ◽  
Near Infrared ◽  
Galactic Center ◽  
Massive Black Hole ◽  
Data Set ◽  
Stellar Orbits ◽  
Supermassive Black Hole ◽  
Near Future ◽  
Precision Astrometry

AbstractIn 1992, we obtained the first observations of S2 a star close to the supermassive black hole at the Galactic Center. In 2002, S2 passed its periastron and in 2007, it completed a first fully observed revolution. This orbit allowed us to determine the mass of and the distance to the supermassive black hole with unprecedented accuracy. Here we present a re-analysis of the data set, enhancing the astrometric accuracy to 0.5 mas and increasing the number of well-determined stellar orbits to roughly 15. This allows to constrain the extended mass distribution around the massive black hole and will lead in the near future to the detection of post-Newtonian effects. We will also give an outlook on the potential of interferometric near-infrared astrometry with 10 microarcsecond accuracy from the VLTI.

Infrared space astrometry mission for survey of the Galactic nuclear bulge: Small-JASMINE

2019 ◽  
Vol 14 (S353) ◽  
pp. 51-53
Author(s):  
Naoteru Gouda ◽  
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Galactic Center ◽  
Scientific Objective ◽  
Satellite Mission ◽  
Infrared Band ◽  
Supermassive Black Hole ◽  
Space Astrometry ◽  
Galactic Structures ◽  
Astrometric Data

AbstractSmall-JASMINE will provide astrometric data with high precisions in a near infrared band for stars in the Galactic nuclear bulge and other specific targets. The primary scientific objective is to carry out the Galactic Center Archeology by exploring the Galactic nuclear bulge that leads to the elucidation of the Galactic structures and the evolution of the supermassive black hole at the center. Small-JASMINE has been selected as the unique candidate for the competitive 3rd M-class science satellite mission by ISAS/JAXA. The launch date is mid-2020s.

scholarly journals A geometric distance measurement to the Galactic center black hole with 0.3% uncertainty

2019 ◽  
Vol 625 ◽  
pp. L10 ◽  
Author(s):  
◽  
R. Abuter ◽  
A. Amorim ◽  
M. Bauböck ◽  
J. P. Berger ◽  
...  
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Galactic Center ◽  
Accurate Determination ◽  
Massive Black Hole ◽  
Geometric Distance ◽  
Significance Level ◽  
Beam Combiner ◽  
Infrared Interferometry ◽  
Sgr A

We present a 0.16% precise and 0.27% accurate determination of R0, the distance to the Galactic center. Our measurement uses the star S2 on its 16-year orbit around the massive black hole Sgr A* that we followed astrometrically and spectroscopically for 27 years. Since 2017, we added near-infrared interferometry with the VLTI beam combiner GRAVITY, yielding a direct measurement of the separation vector between S2 and Sgr A* with an accuracy as good as 20 μas in the best cases. S2 passed the pericenter of its highly eccentric orbit in May 2018, and we followed the passage with dense sampling throughout the year. Together with our spectroscopy, in the best cases with an error of 7 km s−1, this yields a geometric distance estimate of R0 = 8178 ± 13stat. ± 22sys. pc. This work updates our previous publication, in which we reported the first detection of the gravitational redshift in the S2 data. The redshift term is now detected with a significance level of 20σ with fredshift = 1.04 ± 0.05.

scholarly journals Modeling the orbital motion of Sgr A*’s near-infrared flares

2020 ◽  
Vol 635 ◽  
pp. A143 ◽  
Author(s):  
◽  
M. Bauböck ◽  
J. Dexter ◽  
R. Abuter ◽  
A. Amorim ◽  
...  
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Near Infrared ◽  
Galactic Center ◽  
Orbital Motion ◽  
Plane Motion ◽  
Infrared Observations ◽  
Out Of Plane ◽  
Sgr A ◽  
Astrometric Data

Infrared observations of Sgr A* probe the region close to the event horizon of the black hole at the Galactic center. These observations can constrain the properties of low-luminosity accretion as well as that of the black hole itself. The GRAVITY instrument at the ESO VLTI has recently detected continuous circular relativistic motion during infrared flares which has been interpreted as orbital motion near the event horizon. Here we analyze the astrometric data from these flares, taking into account the effects of out-of-plane motion and orbital shear of material near the event horizon of the black hole. We have developed a new code to predict astrometric motion and flux variability from compact emission regions following particle orbits. Our code combines semi-analytic calculations of timelike geodesics that allow for out-of-plane or elliptical motions with ray tracing of photon trajectories to compute time-dependent images and light curves. We apply our code to the three flares observed with GRAVITY in 2018. We show that all flares are consistent with a hotspot orbiting at R ∼ 9 gravitational radii with an inclination of i ∼ 140°. The emitting region must be compact and less than ∼5 gravitational radii in diameter. We place a further limit on the out-of-plane motion during the flare.

scholarly journals Interpretation of the power spectrum of the quiet Sun photospheric turbulence

2020 ◽  
Vol 499 (4) ◽  
pp. 5363-5365
Author(s):  
Itzhak Goldman
Keyword(s):  
Power Spectrum ◽  
Power Law ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Spatial Scales ◽  
Power Spectra ◽  
Effective Width ◽  
Turbulent Layer ◽  
Quiet Sun ◽  
Magnetic Field Turbulence

ABSTRACT Observational power spectra of the photospheric magnetic field turbulence, of the quiet-sun, were presented in a recent paper by Abramenko & Yurchyshyn. Here, I focus on the power spectrum derived from the observations of the Near InfraRed Imaging Spectrapolarimeter operating at the Goode Solar Telescope. The latter exhibits a transition from a power law with index −1.2 to a steeper power law with index −2.2, for smaller spatial scales. This paper presents an interpretation of this change. Furthermore, this interpretation provides an estimate for the effective width of the turbulent layer probed by the observations. The latter turns out to be practically equal to the depth of the photosphere.

Sign in / Sign up

Export Citation Format

Share Document