- ID:
- ivo://nasa.heasarc/cygtevcxo
- Title:
- Cygnus TeV Source Chandra X-Ray Point Source Catalog
- Short Name:
- CYGTEVCXO
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- A 50 ks Chandra observation of the unidentified TeV source in Cygnus reported by the High Energy Gamma-Ray Astronomy (HEGRA) collaboration reveals no obvious diffuse X-ray counterpart. However, 240 pointlike X-ray sources are detected within or nearby the extended TeV J2032+4130 source region, of which at least 36 are massive stars and two may be radio emitters. That the HEGRA source is a composite, having as a counterpart the multiple pointlike X-ray sources that are observed, cannot be ruled out. Indeed, the distribution of pointlike X-ray sources appears nonuniform and concentrated broadly within the extent of the TeV source region. A hypothesis is offered for the origin of the very high energy gamma-ray emission in Cyg OB2 based on the local acceleration of TeV-range cosmic rays and the differential distribution of OB versus less massive stars in this association. The region of TeV J2032+4130 was observed by Chandra on 2004 July 12 for a total effective exposure time of 48,728 seconds using the Advanced CCD Imaging Specrometer imaging array (ACIS-I). The observation was centered on J2000.0 coordinates (RA, Dec) = )20 32 07.0, +41 30 30). This table contains the list of the 240 pointlike sources which were detected in the ACIS-I data and their 2MASS near-IR counterparts, if any are found within 3" of the X-ray sources. 130 (54%) of the 240 X-ray sources have 2MASS counterparts within these error radii. This table was created by the HEASARC in February 2007 based on the electronic version of Table 1 from the above reference which was obtained from the ApJ website. This is a service provided by NASA HEASARC .
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Search Results
4552. Cygnus-X Archive
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/Cygnus-X/CygXArchive
- Title:
- Cygnus-X Archive
- Short Name:
- CygXArchive
- Date:
- 01 Oct 2018 20:27:17
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Cygnus-X project is a Cycle 4 Legacy program (PID 40184) on the Spitzer Space Telescope. The survey imaged a ~24 square degree region centered near 20:30:25, +40:00 (J2000) with IRAC and the MIPS 24 micron band. Two catalog data products are provided, the Catalog and the Archive. The Catalog has more stringent constraints on S/N and detections in multiple bands, so in principle it is more reliable than the Archive. However, the lists differ mostly in the sources included at the faint end, including more sources that satisfy the S/N criterion in both IRAC 3.6 and 4.5 m bands. A detailed comparison between the Archive sources and the mosaics indicates that most of the sources are likely real, but a conservative estimate of the S/N has pushed them slightly outside of the requirement for inclusion in the Catalog.
4553. Cygnus-X Catalog
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/Cygnus-X/CygXCatalog
- Title:
- Cygnus-X Catalog
- Short Name:
- CygXCatalog
- Date:
- 01 Oct 2018 20:27:17
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Cygnus-X project is a Cycle 4 Legacy program (PID 40184) on the Spitzer Space Telescope. The survey imaged a ~24 square degree region centered near 20:30:25, +40:00 (J2000) with IRAC and the MIPS 24 micron band. Two catalog data products are provided, the Catalog and the Archive. The Catalog has more stringent constraints on S/N and detections in multiple bands, so in principle it is more reliable than the Archive. However, the lists differ mostly in the sources included at the faint end, including more sources that satisfy the S/N criterion in both IRAC 3.6 and 4.5 m bands. A detailed comparison between the Archive sources and the mosaics indicates that most of the sources are likely real, but a conservative estimate of the S/N has pushed them slightly outside of the requirement for inclusion in the Catalog.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A1
- Title:
- Cygnus-X CO and SiO outflows datacubes
- Short Name:
- J/A+A/570/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a PdBI study of six massive dense cores in Cygnus-X, with CO (2-1) and SiO (2-1) emission. We studied the outflows of the individual protostars with CO (Duarte-Cabral et al., 2013A&A...558A.125D), and investigated the interstellar shocks responsible for the SiO emission (in Duarte-Cabral et al. 2014A&A...570A...1D).
4555. Cygnus X-3 IR spectra
- ID:
- ivo://CDS.VizieR/J/MNRAS/308/473
- Title:
- Cygnus X-3 IR spectra
- Short Name:
- J/MNRAS/308/473
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present four epochs, A, B, C and D, of resolution ({lambda}/{delta}{lambda}) = 1200, 2.12 micron spectroscopy of the peculiar X-ray binary Cygnus X-3. About a half dozen spectra taken with resolution 900, and at 1.62 micron are also included. These data were obtained using the FSpec near-infrared spectrometer (Williams, D., Thompson, C.L., Rieke, G.H., Montgomery, E. 1993, Proc. SPIE 1308, 482) on the Multiple Mirror Telescope (MMT). The MMT is located at an elevation of 2600 m at the top of Mt. Hopkins in southern Arizona and is jointly operated by the Smithsonian Astrophysics Observatory and the University of Arizona. The spectra are stored as ascii files, listing wavelength in Angstroms and relative flux. Each file contains a five line header, giving the UT, Heliocentric Julian date and phase of the X-ray system at the start of the integration, followed by the data points. Additional information about the spectra can be obtained in the paper.
4556. Cyg OB2 XMM observations
- ID:
- ivo://CDS.VizieR/J/A+A/536/A31
- Title:
- Cyg OB2 XMM observations
- Short Name:
- J/A+A/536/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cyg OB2 is one of the most massive associations of O-type stars in our Galaxy. Despite the large interstellar reddening towards Cyg OB2, many studies, spanning a wide range of wavelengths, have been conducted to more clearly understand this association. X-ray observations provide a powerful tool to overcome the effect of interstellar absorption and study the most energetic processes associated with the stars in Cyg OB2. We analyse XMM-Newton data to investigate the X-ray and UV properties of massive O-type stars as well as low-mass pre-main sequence stars in Cyg OB2.
4557. Cyg X-1 JK light curves
- ID:
- ivo://CDS.VizieR/J/other/PZ/28.7
- Title:
- Cyg X-1 JK light curves
- Short Name:
- J/other/PZ/28.7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our long-term (13 years) J and K photometry of the X-ray binary Cyg X-1. The object's JK variability amplitudes were less than 0.2mag. The J and K orbital light curves are appreciably asymmetric in quadratures. The secondary minimum is deeper, in comparison to the primary, and it is probable that the star becomes hotter at secondary minima.
- ID:
- ivo://CDS.VizieR/J/A+A/447/245
- Title:
- Cyg X-1 Spectral Evolution 1999-2004
- Short Name:
- J/A+A/447/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Continuing the observational campaign initiated by our group, we present the long term spectral evolution of the Galactic black hole candidate Cygnus X-1 in the X-rays and at 15GHz. We present about 200 pointed observations taken between early 1999 and late 2004 with the Rossi X-ray Timing Explorer and the Ryle radio telescope. The X-ray spectra are remarkably well described by a simple broken power law spectrum with an exponential cutoff. Physically motivated Comptonization models, e.g., by Titarchuk (1994ApJ...434..570T, compTT) and by Coppi (1999, eqpair), can reproduce this simplicity; however, the success of the phenomenological broken power law models cautions against ``over-parameterizing'' the more physical models. Broken power law models reveal a significant linear correlation between the photon index of the lower energy power law and the hardening of the power law at about 10keV. This phenomenological soft/hard power law correlation is partly attributable to correlations of broad band continuum components, rather than being dominated by the weak hardness/reflection fraction correlation present in the Comptonization model. Specifically, the Comptonization models show that the bolometric flux of a soft excess (e.g., disk component) is strongly correlated with the compactness ratio of the Comptonizing medium, with L_disk{propto}(l_h_/l_s_)^-0.19^. Over the course of our campaign, Cyg X-1 transited several times into the soft state, and exhibited a large number of ``failed state transitions''. The fraction of the time spent in such low radio emission/soft X-ray spectral states has increased from about 10% in 1996-2000 to about 34% since early 2000. We find that radio flares typically occur during state transitions and failed state transitions (at l_h_/l_s_~3), and that there is a strong correlation between the 10-50keV X-ray flux and the radio luminosity of the source. We demonstrate that rather than there being distinctly separated states, in contrast to the timing properties the spectrum of Cyg X-1 shows variations between extremes of properties, with clear cut examples of spectra at every intermediate point in the observed spectral correlations.
- ID:
- ivo://CDS.VizieR/J/A+A/652/A49
- Title:
- CzeV404 Her light curves and spectra
- Short Name:
- J/A+A/652/A49
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present a new study of the eclipsing cataclysmic variable CzeV404 Her (Porb=0.098d) located in the period gap. This report aims to determine the object's origin, system parameters and probe the system's accretion flow structure. We conducted simultaneous time-resolved photometric and spectroscopic observations of CzeV404 Her. We applied our light curve modeling techniques and the Doppler tomography method to determine the system parameters and analyse the structure of the accretion disk. We found that the system has a massive white dwarf M_WD_=1.00(2)M_{sun}_, a mass ratio of q=0.16, and a relatively hot secondary with an effective temperature T_2_=4100(50)K. The system inclination is 78{deg}. The accretion disk spreads out to the tidal limitation radius and has an extended hot spot/line region. The hot spot/line is hotter than the rest of the disk's outer part in quiescence or intermediate state but does not stand out completely from the disk flux in (super)outbursts. We claim that this object represents a link between two distinct classes of SU UMa-type and SW Sex-type cataclysmic variables. The accretion flow structure in the disk corresponds to the SW Sex systems, but the physical conditions inside the disk passed into behaviors of SU UMa-type objects.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A63
- Title:
- CzeV1731 times of eclipses and radial velocities
- Short Name:
- J/A+A/642/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of the relatively bright (V=10.5mag), doubly eclipsing 2+2 quadruple system CzeV1731. This is the third known system of its kind, in which the masses are determined for all four stars and both the inner and outer orbits are characterized. The inner eclipsing binaries are well-detached systems moving on circular orbits: pair A with period P_A_=4.10843d and pair B with P_B_=4.67552d. The inner binaries contain very similar components (q~1.0), making the whole system a so-called double twin. The stars in pair B have slightly larger luminosities and masses and pair A shows deeper eclipses. All four components are main-sequence stars of F/G spectral type. The mutual orbit of the two pairs around the system barycenter has a period of about 33 yr and an eccentricity of about 0.38. However, further observations are needed to reveal the overall architecture of the whole system, including the mutual inclinations of all orbits. This is a promising target for interferometry to detect the double at about 59mas and {DELTA}Mbol<1mag.