- ID:
- ivo://CDS.VizieR/J/ApJS/95/401
- Title:
- Clusters of galaxies position angles
- Short Name:
- J/ApJS/95/401
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The position angles of a large number of Abell and Shectman clusters, identified in the Lick map as surface galaxy-density enhancements, are estimated. I determine the major axis orientation of a total of 637 clusters, of which 448 are Shectman clusters (202 of which are also Abell clusters) and 189 are Abell clusters not originally detected by Shectman due to his adopted density threshold. Using published redshifts for 277 of these clusters I have detected strong nearest neighbor alignments over scales up to ~15h^-1^Mpc at a>~2.5-3{sigma} significance level, while quite weak alignments are detected even up to ~60h^-1^Mpc. A more significant alignment signal (~4{sigma}) is detected among all neighbors residing in superclusters and having separations <~ 10h^-1^Mpc. Again, weaker but significant alignments are found when larger separations are considered. Since my cluster sample is neither volume limited nor redshift complete (which would have tended to wash out any real alignment signal), the alignments detected should reflect a real and possibly a stronger underline effect.
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- ID:
- ivo://CDS.VizieR/J/A+AS/110/313
- Title:
- Clusters of galaxies properties. II.
- Short Name:
- J/A+AS/110/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present F band photometry, from digitized 48-inch Palomar plates, of 1167 galaxies brighter than m_3_ +3 in 10 Abell clusters. For each galaxy, absolute coordinates, magnitude, size, ellipticity and orientation are given. For each cluster we provide finding charts and contour maps of the galaxy surface density.
- ID:
- ivo://CDS.VizieR/J/ApJ/767/51
- Title:
- Clusters of starburst galaxy NGC4214
- Short Name:
- J/ApJ/767/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The production rate of ionizing photons in young (<=8Myr), unresolved stellar clusters in the nearby irregular galaxy NGC 4214 is probed using multi-wavelength Hubble Space Telescope WFC3 data. We normalize the ionizing photon rate by the cluster mass to investigate the upper end of the stellar initial mass function (IMF). We have found that within the uncertainties the upper end of the stellar IMF appears to be universal in this galaxy, and that deviations from a universal IMF can be attributed to stochastic sampling of stars in clusters with masses {<~}10^3^M_{sun}_. Furthermore, we have found that there does not seem to be a dependence of the maximum stellar mass on the cluster mass. We have also found that for massive clusters, feedback may cause an underrepresentation in H{alpha} luminosities, which needs to be taken into account when conducting this type of analysis.
- ID:
- ivo://nasa.heasarc/le
- Title:
- CMA Catalog Central 6 Arcmin
- Short Name:
- LE
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table contains results from the LE telescope for only the central 6 arc-minutes. It is the same as the CMA database in every other respect. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/A+A/503/827
- Title:
- 6cm and 11cm polarisation maps of SNR G65.2+5.7
- Short Name:
- J/A+A/503/827
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- SNR G65.2+5.7 is one of few supernova remnants (SNRs) that have been optically detected. It is exceptionally bright in X-rays and the optical [O III]-line. Its low surface brightness and large diameter ensure that radio observations of SNR G65.2+5.7 are technically difficult and thus have hardly been completed. Many physical properties of this SNR, such as spectrum and polarization, can only be investigated by radio observations.
- ID:
- ivo://CDS.VizieR/J/A+A/482/783
- Title:
- 6cm and 11cm polarisation maps of SNR S147
- Short Name:
- J/A+A/482/783
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- S147 is a large faint shell-type supernova remnant (SNR) known for its remarkable spectral break at cm-wavelength, which is an important physical property to characterize SNR evolution. However, the spectral break is based on radio observations with limited precision. New sensitive observations at high frequencies are required for a detailed study of the spectral properties and the magnetic field structure of S147.
- ID:
- ivo://CDS.VizieR/J/other/Ser/184.93
- Title:
- 6cm and 3cm sources in SMC
- Short Name:
- J/other/Ser/184.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present two new catalogues of radio-continuum sources in the field of the Small Magellanic Cloud (SMC). These catalogues contain sources found at 4800MHz (λ=6cm) and 8640MHz (λ=3cm). Some 457 sources have been detected at 3cm with 601 sources at 6cm created from new high-sensitivity and resolution radio-continuum images of the SMC from Crawford et al. (<A HREF="http://simbad.cds.unistra.fr/simbad/sim-ref?bibcode=2011SerAJ.183...95C%202011SerAJ.183...95C">2011SerAJ.183...95C 2011SerAJ.183...95C</A>).
- ID:
- ivo://CDS.VizieR/J/ApJS/177/515
- Title:
- 6cm and 20cm survey of Galactic Center
- Short Name:
- J/ApJS/177/515
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the results of a millijansky sensitivity VLA survey of roughly 1deg^2^ near the Galactic center at 6 and 20cm. Catalogs of compact and filamentary structures are given and compared to previous surveys of the region. Eight of the unusual nonthermal radio filaments are detected in 6cm polarized emission; three of these are the first such detections, confirming their nonthermal nature. This survey found emission from a filament at (l,b)=(359.1,0.75), or a projected distance from Sgr A* of 200pc, greatly extending the latitude range observed with such features. There is also new evidence for spatial gradients in the 6/20cm spectral indices of some filaments, and we discuss models for these gradients. In studying compact sources, the combination of spectral index and polarization information allows us to identify pulsar candidates and compact HII regions in the survey. There is also some evidence that the flux measurements of compact sources may be affected by electron scattering from the interstellar medium in the central few hundred parsecs of the Galaxy.
- ID:
- ivo://nasa.heasarc/cmaob1nir
- Title:
- CMa OB1 XMM-Newton Point Source Near-Infrared Counterpart Properties Catalog
- Short Name:
- CMAOB1NIR
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Canis Major OB1 association has an intriguing scenario of star formation, especially in the region called Canis Major R1 (CMa R1) traditionally assigned to a reflection nebula, but in reality an ionized region. The authors focused on the young stellar population associated with CMa R1, for which previous results from ROSAT, optical, and near-infrared data had revealed two stellar groups with different ages, suggesting a possible mixing of populations originated from distinct star formation episodes (see the <a href="/W3Browse/rosat/cmar1xray.html">table CMAR1XRAY</a>). The observations performed with XMM-Newton resulted in a sample of 387 X-ray sources (187, 84, 37, and 79 in Fields E, C, S , and W, respectively), 340 of which have one or more NIR (2MASS) counterparts. This table contains the 2MASS photometry, estimates of age and mass, and infrared classification of members of the CMa R1 region and counterparts to X-ray sources, based on 2MASS and WISE data. The authors also used X-ray data to characterize the detected sources (387 sources) according to hardness ratios, light curves, and spectra (see the associated table <a href="/W3Browse/xmm-newton/cmaob1xmm.html">CMAOB1XMM</a>). For this work, four fields (each about 30-arcmin diameter with some overlap) were defined. These fields are located inside the arc-shaped ionized nebula, next to Z CMa - Field E (east); around GU CMa - Field W (west); and between both - Field C (center) and Field S (south), as shown in Figure 1 of the reference paper. <pre> RA(J2000) | Dec(J2000) | Designation(s) 07 04 18.3 | -11 27 24.0 | CMa cluster east (Field E) 07 02 58.4 | -11 34 44.7 | CMa cluster center (Field C) 07 02 29.5 | -11 47 12.4 | CMa cluster south (Field S) 07 01 23.0 | -11 19 56.6 | CMa cluster west (Field W) </pre> The authors have selected NIR counterparts by searching the 2MASS catalog for candidates located less that 10'' away from the nominal X-ray source positions. No counterpart was found for 45 sources. Candidates for which the distance seems to be incompatible with the CMaR1 molecular cloud were disregarded. This table includes the complete list of NIR counterparts, however the authors only consider as reliable those flagged as 'AAA' in the 2MASS catalog (i.e., with S/N > 10, magnitude errors <0.1 mag, and above the JHK completeness limits), given by the twomass_flags field in this table. There are 340 such reliable NIR counterparts for 290 X-ray sources, including 46 X-ray sources with multiple counterpart candidates. X-ray and NIR data have revealed that most (79%) of the XMM-Newton sources are probable members of CMa R1. The combination of the results from both analyses can confirm their young nature. On the other hand, 21% of the XMM-Newton sample are probably field objects. Among these, 6% (23/387) have infrared counterparts that probably are foreground stars and 4% (17/387) have counterparts that are too faint (bad quality data) without reliable classification. The other 11% of undefined sources (44/387) do not have 2MASS data because they are classified as possible background objects. The authors have seen that the XMM-Newton error boxes may include multiple NIR counterparts. In such cases, they restricted the comparative analysis to the 158 X-ray sources of their "best sample" that are associated with a single NIR counterpart, as described in Section 4.3 of the reference paper. A distance of 1 kpc to CMa OB1 is assumed for this table. This table was created by the HEASARC in October 2018 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/609/A127">CDS Catalog J/A+A/609/A127</a> file tableb2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cmaob1xmm
- Title:
- CMa OB1 XMM-Newton X-Ray Point Source Catalog
- Short Name:
- CMAOB1XMM
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Canis Major OB1 association has an intriguing scenario of star formation, especially in the region called Canis Major R1 (CMa R1) traditionally assigned to a reflection nebula, but in reality an ionized region. The authors focused on the young stellar population associated with CMa R1, for which previous results from ROSAT, optical, and near-infrared data had revealed two stellar groups with different ages, suggesting a possible mixing of populations originated from distinct star formation episodes (see the <a href="/W3Browse/rosat/cmar1xray.html">table CMAR1XRAY</a>). The authors used X-ray data to characterize the detected sources according to hardness ratios, light curves, and spectra. They also provided estimates of mass and age, using the information from likely counterparts based on the 2MASS catalogue. The 2MASS-derived data on the counterparts, where matched, are provided in the <a href="/W3Browse/xmm-newton/cmaob1nir.html">associated table (CMAOB1NIR)</a>. This table contains a catalog of 387 XMM-Newton sources, of which 78% are confirmed as members or probable members of the CMa R1 association. Flares (or similar events) were observed for 13 sources and the spectra of 21 bright sources could be fitted by a thermal plasma model. Mean values of fits parameters were used to estimate X-ray luminosities. The authors found a minimum value of log(L<sub>X</sub> [erg/s]) = 29.43, indicating that the sample of low-mass stars (M<sub>*</sub> <= 0.5 M<sub>sun</sub>), which are faint X-ray emitters, is incomplete. Among the 250 objects selected as the complete subsample (defining a "best sample"), 171 are found to the east of the cloud, near Z CMa and dense molecular gas, of which 50% of them are young (<5Myr) and 30% are older (>10Myr). The opposite happens to the west, near GU CMa, in areas lacking molecular gas: among 79 objects, 30% are young and 50% are older. These findings confirm that a first episode of distributed star formation occurred in the whole studied region ~10Myr ago and dispersed the molecular gas, while a second, localized episode (<5Myr) took place in the regions where molecular gas is still present. For this work, four fields (each about 30-arcmin diameter with some overlap) were observed with the XMM-Newton satellite. These fields are located inside the arc-shaped ionized nebula, next to Z CMa - Field E (east); around GU CMa - Field W (west); and between both - Field C (center) and Field S (south), as shown in Figure 1 of the reference paper. These observations were performed with the EPIC cameras (MOS1, MOS2, and PN) in full frame mode with a medium filter. The C, W, and S fields had an exposure time without background corrections of about 30 ks while field E had 40 ks. <pre> RA(J2000) | Dec(J2000) | Designation(s) 07 04 18.3 | -11 27 24.0 | CMa cluster east (Field E) 07 02 58.4 | -11 34 44.7 | CMa cluster center (Field C) 07 02 29.5 | -11 47 12.4 | CMa cluster south (Field S) 07 01 23.0 | -11 19 56.6 | CMa cluster west (Field W) </pre> This table was created by the HEASARC in October 2018 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/609/A127">CDS Catalog J/A+A/609/A127</a> file tableb1.dat. This is a service provided by NASA HEASARC .