"northern" ukidss and southern vista vhs dr1 - post 4

metpaper@Safe-mail.net Mar 3, 2012

UKIDSS has been around a while, with data releases occuring every year or so, and to some extent it can be thought of as a "deeper", fainter, 2MASS mostly for parts of the sky accessible from the Northern hemisphere.

It also includes an area acronymed as LAS which overlaps with SDSS fields.

The ukidss.tdf file in http://wikisend.com/download/397990/newtdf.zip is for ukidss, but ukidss isn't accessible via vizier. However, the Royal Observatory at Edingburgh serves the data.

Basically, you go here :-


For the Large Area Survey you choose that from the "choose survey from list" dropdown.

The table you choose on the next drop down is "source table (merged catalogue)".

Then you put in your coords: plots of coverage for dr7plus are here :- http://surveys.roe.ac.uk/wsa/dr7plus_release.html (tick the blue links for the relevant survey), and an area in arcminutes to return data for.

The data format you need is ASCII.

File compression is (none)

Further down the page in an input entitled "Select" is the word default. You replace that word with :-

ra, dec, j_1apermag3, j_1apermag3err, kapermag3, kapermag3err

then submit.

On the resulting page you scroll down and save the CSV file, it will read something like this :-

# Results of Query: Database UKIDSSDR7PLUS 03/03/12 20:19
# SELECT ra,dec,j_1apermag3,j_1apermag3err,kapermag3,kapermag3,
# 2*DEGREES(ASIN(sqrt(power(-0.8774701330051641-cx,
# 2)+power(0.4470933639373926-cy,2)+power(0.17364817766693033-cz,
# 2))/2))*60 as distance FROM lasSource WHERE dec > 9.9 and dec < 10.1
# and RA >= 152.8984259281104 and RA <= 153.1015740718896 and ((cx *
# -0.8774701330051641 + cy * 0.4470933639373926 + cz *
# 0.17364817766693033 ) >= 0.9999984769132877)
# Column Headers at start of file AND below
# ra,dec,j_1apermag3,j_1apermag3err,kapermag3,kapermag3,distance
+152.9881971, +9.9080476, -9.999995E008, -9.999995E008, +18.041914, +18.041914, +5.5610608
+153.0634309, +9.9691088, -9.999995E008, -9.999995E008, +18.080414, +18.080414, +4.1814444
+153.0468959, +9.9701228, +18.970232, +0.090164, +17.466343, +17.466343, +3.3004075
+152.9696548, +10.0148138, -9.999995E008, -9.999995E008, -9.999995E008, -9.999995E008, +2.0012227
+153.0350786, +10.0150831, +17.562614, +0.025462, +16.186453, +16.186453, +2.2616482
+152.9445791, +10.0164728, -9.999995E008, -9.999995E008, +18.595823, +18.595823, +3.4205590
+152.9600832, +10.0184792, -9.999995E008, -9.999995E008, +18.361956, +18.361956, +2.6061670
+153.0377828, +10.0686091, +18.518032, +0.059672, +17.768808, +17.768808, +4.6828467
+153.0487178, +9.9149841, -9.999995E008, -9.999995E008, +18.388563, +18.388563, +5.8573544
+153.0011437, +9.9191988, -9.999995E008, -9.999995E008, +18.356773, +18.356773, +4.8485454

if you maintain a file called ukidss.dat in your Guide directory then you can insert the results_etc.csv file's contents into that file, or cut and paste it into it, by launching it into a text editor first.

ukidss.tdf, if kept in the Guide directory, displays small red triangles and gives the above data except for the null data magnitudes starting -9.999etc. The hashed lines can be deleted or simply ignored during file insert if you want to use the least effort, as the tdf script language treats anything commencing with # as a comment, not to be acted upon. Position, ra and dec, and J and K magnitudes are given down to mags 19 to 20.

A linkout to 1 arcmin image cutouts of the field is also in More Info, with possibility to download fits files of said.

For GPS, Galactic Plane Survey as the selected survey the Select line is

ra, dec, japermag3, japermag3err, k_1apermag3, k_1apermag3err (from memory)

Clicking on shema browser link in the sidebar gives the table structures.

A bit esoteric and a bit infrared, and if a star is in this catalogue but not in ppmxl or similar, it's likely optically invisible, so not much practical use.

The upside is this solution is generic. It seems this server, which is quite a simple one to use, will be coming into force more in future, from the look of things, for other data.

For instance, ESO has just recently made public the VHS data release 1 from the VISTA programme (also shows current data release sky coverage) :-


This is brand new Southern Hemisphere stuff, and will be the equivalent of the Northern UKIDSS, and some aspects of VISTA will also cover a Southern Hemisphere equivalent of the SDSS (or is that VPHAS+ from the VST, part of the VLT, also new and upcoming, it's all a bit confusing really, and I think it will be a bit from both?).

Anyway, that data is served via http://horus.roe.ac.uk:8080/vdfs/Vregion_form.jsp

And you can immediately see the similarity with UKIDSS data server, which was also via ROE.

There's not "much" in there as of yet ("only" millions of stars), but if you select the VISTA programme VHS from the dropdown you get the current DR1 database release selected. Then as above you choose merged source table, give an RA and Dec and search radius, choose ASCII file, no compression, and this time in the SELECT box this (instead of "default") :-

ra, dec, japermag3, japermag3err, ksapermag3, ksapermag3err

and if you add the results file contents to a file called vhs.dat in the Guide directory and place vhs.tdf from the above zip file also in the Guide directory you again get little red triangles giving J and Ks (this time) magnitudes down to about 20 where they exist.

And just to highlight the similarity, here's an example data output for that one :-

# ra,dec,japermag3,japermag3err,ksapermag3,ksapermag3err,distance
# Results of Query: Database VHSDR1 03/03/12 20:47
# SELECT ra, dec, japermag3, japermag3err, ksapermag3, ksapermag3err,
# 2*DEGREES(ASIN(sqrt(power(-1.826907083767072E-16-cx,
# 2)+power(-0.9945218953682733-cy,2)+power(-0.10452846326765346-cz,
# 2))/2))*60 as distance FROM vhsSource WHERE dec > -6.016666666666667
# and dec < -5.9833333333333325 and RA >= 269.98324101558796 and RA <=
# 270.01675898441204 and ((cx * -1.826907083767072E-16 + cy *
# -0.9945218953682733 + cz * -0.10452846326765346 ) >=
# 0.9999999576920253)
# Column Headers at start of file AND below
# ra,dec,japermag3,japermag3err,ksapermag3,ksapermag3err,distance
+269.9894560, -5.9934519, +15.390454, +0.005997, +14.598326, +0.009614, +0.7417685
+269.9876143, -6.0069881, +19.991451, +0.265247, -9.999995E008, -9.999995E008, +0.8497164
+269.9900221, -6.0071514, +20.176443, +0.311567, -9.999995E008, -9.999995E008, +0.7338963
+270.0042400, -6.0057230, +18.961191, +0.102601, +17.740840, +0.156560, +0.4265228
+269.9950840, -6.0066921, +17.646013, +0.032690, +17.075012, +0.085670, +0.4972674
+270.0027075, -5.9884653, +19.232695, +0.130958, +18.024155, +0.202942, +0.7106910
+269.9992237, -5.9908538, +18.500660, +0.068095, +17.526487, +0.129634, +0.5507211
+270.0130013, -5.9916883, +14.535217, +0.003561, +13.595933, +0.004318, +0.9222744

and as new data releases appear, more sky will be covered.

Now, the Southern Hemisphere used to be better covered, but then the CCD based Northern Surveys started, and the Southern Surveys aged a bit. Now the Norhern ones are nearly done, if not finished up entirely, the Southern CCD based deep/faint ones have started up. This is just some of the first data from such to be available for those skies.

Not much practical use as of yet, though there will of course be future VISTA VHS releases, as well as other VISTA datasets. But as I say, this appears to be a base template that with little modification can be used for each new bit of data that will come out, and it will be years before stuff gets onto VizieR (eg SPM4 hasn't gotten to VizieR yet, and although UKIDSS data release 5 has been pending at CDS for some time, and images from said available via the CDS Aladin service, the data has not reached VizieR yet, whilst the latest public release is date release 7).