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--- spidx [2017/07/31 11:28] – fdg
+++ spidx [2022/07/25 13:46] (current) – fdg
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+~~NOCACHE~~
+{{htmlmetatags>metatag-keywords=(keywords>astronomy,radio,interferometry,galaxy,galaxies,agn,gmrt,giant,metrewave,telescope,tgss,adr,lofar,mwa,ska,ncra,nrao,astron,leiden,oxford,india,huib,intema,francesco,gasperin,dale,frail,pulsars,150,MHz,1.4,GHz,vla,nvss,megahertz,gigahertz,low,frequency,ionosphere,spam,sources,catalogs,aladin,hips,rms,sensitivity,mjy,vo,virtual,observatory,counts,steep,spectral,index,merging,galaxy,clusters,haloes,halos,relics,interactive,data,products,antenna,dish)}}
 ====== TGSS-NVSS spectral index maps and catalog ======
 === Science team: Francesco de Gasperin (Leiden), Huib T. Intema (Leiden) & Dale A. Frail (NRAO) ===
-We produced a spectral index catalog matching specially re-processed images from two radio surveys at different frequencies: NVSS and TGSS. These surveys were chosen because thy are the most sensitive metre and centimetre wavelength surveys currently available, they both cover a large fraction of the sky, and their separation in frequency provides a large lever arm for spectral index calculation. The resulting catalogue includes >1.4 million entries, making it the largest collection of spectral index information to date. Furthermore, we provide the community a spectral index map of 80% of the sky that can be used to classify radio sources.
+We produced a spectral index catalog matching specially re-processed images from two radio surveys at different frequencies: NVSS and TGSS. These surveys were chosen because they are the most sensitive metre and centimetre wavelength surveys currently available, they both cover a large fraction of the sky, and their separation in frequency provides a large lever arm for spectral index calculation. The resulting catalogue includes >1.4 million entries, making it the largest collection of spectral index information to date. Furthermore, we provide the community a spectral index map of 80% of the sky that can be used to classify radio sources.
 -----
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 {{ wiki:cartoon.png }}
-The final spectral index catalogue has 1 392 563 entries, of which 502,170 (36%) are full detections (source type: S, C, or M), 843,104 (61%) are lower limits (L), and 6,383 (<1%) are upper limits (U). Entries marked as island (I) are 40,906 (3%). The high number of lower limits is due to the higher sensitivity of NVSS with respect to TGSS.
+The final spectral index catalogue has 1 396 515 entries, of which 503,647 (36%) are full detections (source type: S, C, or M), 845,459 (61%) are lower limits (L), and 6,386 (<1%) are upper limits (U). Entries marked as island (I) are 41,023 (3%). The high number of lower limits is due to the higher sensitivity of NVSS with respect to TGSS.
 The spectral index catalog can be downloaded here:
-  * [[http://tgssadr.strw.leidenuniv.nl/spidx/spidxcat_v1.1.fits|FITS]] (193 MB)
+  * [[http://tgssadr.strw.leidenuniv.nl/spidx/spidxcat_v1.1b.fits|FITS]] (111 MB)
 Catalog columns:
@@ Line 48: / Line 53: @@
 ^ Isl_id | -- | Island identification number |
 ^ Source_id | -- | Unique source identification number |
+Some notes are valid only for specific entry types as saved in the S_code column.
 -----
 ===== Spectral index map =====
@@ Line 57: / Line 64: @@
   - a spectral index error map for each //good// pixel that shows the standard deviation of the bootstrapped distribution.
-  * Direct access through the web-based Aladin lite tool (limited functionality; pre-loaded images):
+Direct access through the web-based Aladin lite tool (limited functionality; pre-loaded images):
-    * [[http://tgssadr.strw.leidenuniv.nl/spidx/hips_spidx/|spectral index map]]
+    * [[http://tgssadr.strw.leidenuniv.nl/hips_spidx/|spectral index map]]
-    *[[http://tgssadr.strw.leidenuniv.nl/spidx/hips_spidxerr/|spectral index error map]]
+    * [[http://tgssadr.strw.leidenuniv.nl/hips_spidxerr/|spectral index error map]]
-   * Download and run the [[http://aladin.u-strasbg.fr/java/nph-aladin.pl?frame=downloading|Aladin Desktop tool]] (full functionality)
+Alternatively, download and run the [[http://aladin.u-strasbg.fr/java/nph-aladin.pl?frame=downloading|Aladin Desktop tool]] (full functionality)
+Then use menu //File->Open URL// and enter the following links:
+   * [[http://tgssadr.strw.leidenuniv.nl/hips_spidx/|http://tgssadr.strw.leidenuniv.nl/hips_spidx/]] to load the spectral index images
+   * [[http://tgssadr.strw.leidenuniv.nl/hips_spidxerr/|http://tgssadr.strw.leidenuniv.nl/hips_spidxerr/]] to load the spectral index error images.
-For option 2, use menu //File->Open URL// and enter the following links:
+Fits files are available [[https://tgssadr.strw.leidenuniv.nl/spidx/fits/ | here]].
-   * [[http://tgssadr.strw.leidenuniv.nl/spidx/hips_spidx/|http://tgssadr.strw.leidenuniv.nl/spidx/hips_spidx/]] to load the spectral index images
-   * [[http://tgssadr.strw.leidenuniv.nl/spidx/hips_spidxerr/|http://tgssadr.strw.leidenuniv.nl/spidx/hips_spidxerr/]] to load the spectral index error images
 Two examples of the radio spectral index map produced matching pixel-by-pixel the NVSS and the TGSS maps. Left is the NVSS image, right the TGSS image, at the centre we show the spectral index map:
@@ Line 75: / Line 85: @@
 ===== Acknowledgements =====
-If you use the resources listed in this page, please reference the paper: de Gasperin, Intema & Frail (2017; submitted to MNRAS)
+If you use resources listed in this page, please reference the paper: [[https://ui.adsabs.harvard.edu/abs/2018MNRAS.474.5008D/abstract|de Gasperin, Intema & Frail, MNRAS, 474, 5008 (2018)]].
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