scholarly journals A kinematic analysis of the Giant star-forming Region of N11

2014 ◽  
Vol 10 (S309) ◽  
pp. 153-154
Author(s):  
Sergio Torres-Flores ◽  
Rodolfo Barbá ◽  
Jesús Maíz Apellániz ◽  
Mónica Rubio ◽  
Guillermo Bosch
Keyword(s):  
Gaussian Component ◽  
Line Profiles ◽  
Large Telescope ◽  
Data Set ◽  
Giant Star ◽  
X Ray ◽  
Star Forming ◽  
Very Large Telescope ◽  
Gaussian Fit ◽  
Hα Emission

AbstractIn this work we present high resolution spectroscopic data of the giant star-forming region of N11, obtained with the GIRAFFE instrument at the Very Large Telescope. By using this data set, we find that most of the Hα emission lines profiles in this complex can be fitted by a single Gaussian, however, multiple emission line profiles can be observed in the central region of N11. By adding all the spectra, we derive the integrated Hα profile of this complex, which displays a width (σ) of about 12 km s−1 (corrected by instrumental and thermal width). We find that a single Gaussian fit on the integrated Hα profile leaves remaining wings, which can be fitted by a secondary broad Gaussian component. In addition, we find high velocity features, which spatially correlate with soft diffuse X-ray emission.

scholarly journals On the origin of Supergiant Fast X-ray Transients

2018 ◽  
Vol 14 (S346) ◽  
pp. 193-196
Author(s):  
Swetlana Hubrig ◽  
Lara Sidoli ◽  
Konstantin A. Postnov ◽  
Markus Schöller ◽  
Alexander F. Kholtygin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Stellar Wind ◽  
Longitudinal Magnetic Field ◽  
High Mass ◽  
Large Telescope ◽  
X Ray ◽  
Very Large Telescope ◽  
Low X ◽  
X Ray Binaries

Abstract. A fraction of high-mass X-ray binaries are supergiant fast X-ray transients. These systems have on average low X-ray luminosities, but display short flares during which their X-ray luminosity rises by a few orders of magnitude. The leading model for the physics governing this X-ray behaviour suggests that the winds of the donor OB supergiants are magnetized. In agreement with this model, the first spectropolarimetric observations of the SFXT IGR J11215-5952 using the FORS 2 instrument at the Very Large Telescope indicate the presence of a kG longitudinal magnetic field. Based on these results, it seems possible that the key difference between supergiant fast X-ray transients and other high-mass X-ray binaries are the properties of the supergiant’s stellar wind and the physics of the wind’s interaction with the neutron star magnetosphere.

scholarly journals VERY LARGE TELESCOPE/X-SHOOTER SPECTROSCOPY OF THE CANDIDATE BLACK HOLE X-RAY BINARY MAXI J1659-152 IN OUTBURST

2012 ◽  
Vol 746 (2) ◽  
pp. L23 ◽  
Author(s):  
Ramanpreet Kaur ◽  
Lex Kaper ◽  
Lucas E. Ellerbroek ◽  
David M. Russell ◽  
Diego Altamirano ◽  
...  
Keyword(s):  
Black Hole ◽  
Large Telescope ◽  
X Ray ◽  
Very Large Telescope

scholarly journals Hα Emission Line Profiles in the Spectrum of Algol

1980 ◽  
Vol 88 ◽  
pp. 225-227
Author(s):  
C. T. Bolton ◽  
Donna J. Zubrod
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Line Profiles ◽  
Data Set ◽  
Orbital Phase ◽  
Hα Emission ◽  
Emission Line Profile

We have investigated variations in the strength and profile of the Hα emission line in the spectrum of Algol using 145 16 A° mm−1 spectrograms obtained during the period September, 1976 to December, 1977. The Hα emission line profile has been extracted by subtracting the absorption contributions of the three stars in the system. The resulting data set has been analyzed to look for variations related to orbital phase as well as shorter and longer term variations.

scholarly journals Recent progress in understanding the hot and warm gas phases in the halos of star-forming galaxies

2003 ◽  
Vol 212 ◽  
pp. 612-619 ◽  
Author(s):  
David K. Strickland ◽  
Timothy M. Heckman ◽  
Edward J.M. Colbert ◽  
Charles G. Hoopes ◽  
Kimberley A. Weaver
Keyword(s):  
Plasma Diagnostics ◽  
Recent Progress ◽  
Massive Star ◽  
Physical Origin ◽  
Absorption And Emission ◽  
X Ray ◽  
Star Forming ◽  
Gas Phases ◽  
Hα Emission ◽  
Far Ultraviolet

In this contribution we present a few selected examples of how the latest generation of space-based instrumentation — NASA's Chandra X-ray Observatory and the Far-Ultraviolet Spectroscopic Explorer (FUSE) — are finally answering old questions about the influence of massive star feedback on the warm and hot phases of the ISM and IGM. In particular, we discuss the physical origin of the soft thermal X-ray emission in the halos of star-forming and starburst galaxies, its relationship to extra-planar Hα emission, and plasma diagnostics using FUSE observations of O vi absorption and emission.

scholarly journals First results from XILO: XMM-Newton Investigations in the Lambda Orionis star forming region

2009 ◽  
Vol 5 (H15) ◽  
pp. 768-768
Author(s):  
B. Stelzer ◽  
D. Barrado y Navascues ◽  
N. Huelamo ◽  
M. Morales-Calderon ◽  
A. Bayo
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Supernova Explosion ◽  
Central Star ◽  
Young Stars ◽  
Data Set ◽  
X Ray ◽  
Star Forming ◽  
First Results ◽  
Low Mass

The λ Orionis star formation region (1-6 Myr, 400 pc) is a complex of star-forming clouds surrounded by a molecular ring with ~ 5° radius which was probably formed by a supernova explosion (Dolan & Mathieu 2002). For a complete picture of star formation, believed to be determined by the supernova blast, the large-scale distribution of the pre-main sequence population in λ Ori needs to be examined. We have embarked on a multi-wavelength study (XMM-Newton/X-ray, CFHT/optical, Spitzer/IR) of selected areas within this intriguing star-forming complex that enables us to identify young stars and brown dwarfs. Our study comprises various areas within the cloud complex as shown in Fig.1. This data set is among the most extended X-ray surveys carried out with XMM-Newton in a coherent star-forming environment. The XMM-Newton observations combined with optical and IR data reveal the low-mass stellar population down to ~ 0.4 M⊙. For this mass-limited sample, our preliminary analysis confirms the anomalously low disk-fraction of the central star cluster Coll 69, the Eastern extension of its low-mass population pointing towards B 35, and the concentration of young stars in front of B 35. The analysis of the ‘on-cloud field' of B 35 (white in the figure) will show if the cloud is currently forming stars. This will be crucial for determining the star-forming history in the whole λ Ori region.

scholarly journals Wolf–Rayet stars in the Antennae unveiled by MUSE

2020 ◽  
Vol 500 (2) ◽  
pp. 2076-2095
Author(s):  
V M A Gómez-González ◽  
Y D Mayya ◽  
J A Toalá ◽  
S J Arthur ◽  
J Zaragoza-Cardiel ◽  
...  
Keyword(s):  
Stellar Population ◽  
Young Star ◽  
Interacting Galaxies ◽  
Population Synthesis ◽  
Large Telescope ◽  
Single Star ◽  
Star Forming ◽  
Evolutionary Scenario ◽  
Very Large Telescope ◽  
Stellar Population Synthesis

ABSTRACT We present the analysis of archival Very Large Telescope (VLT) Multi-Unit Spectroscopic Explorer (MUSE) observations of the interacting galaxies NGC 4038/39 (a.k.a. the Antennae) at a distance of 18.1 Mpc. Up to 38 young star-forming complexes with evident contribution from Wolf–Rayet (WR) stars are unveiled. We use publicly available templates of Galactic WR stars in conjunction with available photometric extinction measurements to quantify and classify the WR population in each star-forming region, on the basis of its nearly Solar oxygen abundance. The total estimated number of WR stars in the Antennae is 4053 ± 84, of which there are 2021 ± 60 WNL and 2032 ± 59 WC-types. Our analysis suggests a global WC to WN-type ratio of 1.01 ± 0.04, which is consistent with the predictions of the single star evolutionary scenario in the most recent bpass stellar population synthesis models.

scholarly journals Swift X-Ray Telescope and Very Large Telescope Observations of the Afterglow of GRB 041223

2005 ◽  
Vol 622 (2) ◽  
pp. L85-L88 ◽  
Author(s):  
D. N. Burrows ◽  
J. E. Hill ◽  
G. Chincarini ◽  
G. Tagliaferri ◽  
S. Campana ◽  
...  
Keyword(s):  
Large Telescope ◽  
X Ray ◽  
Very Large Telescope

The puzzling afterglow of GRB 050721: a rebrightening seen in the optical but not in the X-ray

2007 ◽  
Vol 365 (1854) ◽  
pp. 1235-1240 ◽  
Author(s):  
L. Angelo Antonelli ◽  
Vincenzo Testa ◽  
Patrizia Romano ◽  
Dafne Guetta ◽  
Ken'ichi Torii ◽  
...  
Keyword(s):  
Density Profile ◽  
Gamma Ray ◽  
Matter Density ◽  
Optical Observations ◽  
Large Telescope ◽  
X Ray ◽  
Very Large Telescope ◽  
Robotic Telescope ◽  
Inner Region ◽  
First Time

We present here the analysis of the early and late multiwavelength afterglow emission, as observed by Swift a small robotic telescope and very large telescope (VLT). We compare early observations with late afterglow observations obtained with Swift and the VLT and we observe an intense rebrightening in the optical band at about 1 day after the burst, which is not present in the X-ray band. The lack of detection in X-ray of such a strong rebrightening at lower energies may be described with a variable external density profile. In such a scenario, the combined X-ray and optical observations allow us to derive that the matter density located at ∼10 17  cm from the burst is approximately a factor of 10 higher than in the inner region. This is the first time in which a rebrightening has been observed in the optical afterglow of a gamma-ray burst that is clearly absent in the X-ray afterglow.

scholarly journals Resolved Mid-Infrared Imaging of AGN: An Isotropic Measure of Intrinsic Power

2009 ◽  
Vol 5 (S267) ◽  
pp. 108-108
Author(s):  
P. Gandhi ◽  
H. Horst ◽  
A. Smette ◽  
S. F. Hönig ◽  
A. Comastri ◽  
...  
Keyword(s):  
Strong Correlation ◽  
Infrared Imaging ◽  
Large Telescope ◽  
Mid Infrared ◽  
X Ray ◽  
Isotropic Measure ◽  
Very Large Telescope

We present a strong correlation between 12μm mid-IR and intrinsic X-ray (2–10 keV) luminosities of local Seyferts. This work is based on new diffraction-limited mid-IR observations with the 8-m Very Large Telescope (VLT), resulting in the least-contaminated core fluxes of 42 Seyferts to date.

Difference Fourier Analysis of Glucose Embedded and Frozen Hydrated Purple Membrane

1982 ◽  
Vol 40 ◽  
pp. 74-75
Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser
Keyword(s):  
Purple Membrane ◽  
Data Set ◽  
High Resolution Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Fourier Techniques ◽  
Versus Protein ◽  
The Difference ◽  
Difference Fourier ◽  
Ideal Method

Although difference Fourier techniques are standard in X-ray crystallography it has only been very recently that electron crystallographers have been able to take advantage of this method. We have combined a high resolution data set for frozen glucose embedded Purple Membrane (PM) with a data set collected from PM prepared in the frozen hydrated state in order to visualize any differences in structure due to the different methods of preparation. The increased contrast between protein-ice versus protein-glucose may prove to be an advantage of the frozen hydrated technique for visualizing those parts of bacteriorhodopsin that are embedded in glucose. In addition, surface groups of the protein may be disordered in glucose and ordered in the frozen state. The sensitivity of the difference Fourier technique to small changes in structure provides an ideal method for testing this hypothesis.

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