Yahoo tells me that there have been too many bounced mails from this group to my email account so it's blocked it, so I've had to set up a temporary one for this.


A couple of weeks ago the WISE preliminary catalog appeared. Not much use to observers, but there is a mass of data, and some of it might be of interest to those with a more outreach and/or educational viewpoint, and the data are fairly easy to get at, and probably a bit topical, if only by default.

Using it was easy enough, and using it via Guide 8 was fine, but one aspect of it kept either crashing Guide (url too long) or not working, so it took me a while to get rid of the redundant, defaulting, HTTP GET keywords to shrink the required urls, and more importantly to get over the word blindness which kept making me miss the second ';' in the image access url, thus truncating it and making it not work properly. ; means 'everything after this point is a comment' in TDF coding, so half the url was always missing on linking.


Using WISE in Guide 8 is easy enough, though just a touch two step, but here goes :-

First of all, in the Guide directory you have a file called gsc22.tdf. Take a copy or backup of this file, for safety, and then edit the original. If problems arise replace edited file with the copy to return to standard.

Open it in a text editor.

If you scroll down it, to about line 300, you will see the start of the 2MASS data from VizieR TDF coding. This will be the tdf we link in from.

Scrolling down just a little further within that tdf we come to a line that says

~r118 1 mp flag: %s\n

add another, new, blank, line after that line.

paste into that line the following line :-

~r 6 1 \n^WISE_DATA//xhttp://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-query?spatial=Cone&radius=600&catalog=wise_prelim_p3as_psd

that is all one line, it starts ~r then there are two spaces then a 6 then three spaces then a 1 then a space then that is followed by all of the part starting \n and ending psd, all on one line.

make another blanks line after that one and then put this line into that :-

~r 6 1 &outfmt=1&selcols=ra,dec,w1mpro,w1sigmpro,w2mpro,w2sigmpro,w3mpro,w3sigmpro,w4mpro,w4sigmpro&objstr=%[3,9]+%[15,9]^\n

same as above, all one line, starts ~r 6 1 &outfmt=1, ends ^\n

NOW, this is based on the standard interrogation route for all IRSA IPAC data access points, which can be used to access all data, see below for an aside on this.

Save this revised GSC22.tdf back into the Guide directory, watch it retains the proper tdf extension etc.

The Wise Preliminary Catalogue isn't all sky as of yet, but is a fair old chunk of it.

Open Guide 8, go somewhere like Sagitta or Cygnus or generally Milky Way.

Zoom into about a degree field or less.

Download the 2MASS data from VizieR via the Toolbar button or Extras Menu.

Right click on a 2MASS object.

Select More Info.

You should now see a red link in more info that says WISE_DATA

Click on it.

A browser window should pop open with the required data, for a radius of 5 arcmins (data fetching may take a few seconds as the data is being looked up in a large database) :-

<http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-query?spatial=Cone&radius=120&catalog=wise_prelim_p3as_psd&outfmt=1&selcols=ra,dec,w1mpro,w1sigmpro,w2mpro,w2sigmpro,w3mpro,w3sigmpro,w4mpro,w4sigmpro&objstr=300.22729+%2023.09604>

That's all one line, no spaces, if email truncates it.

That's the resultant output for a random position in Vulpecula at RA 300.22729 degrees and Dec 23.09604 degrees.

Now, on occasion instead of a flat ascii screen of data you might see a webpage with information and links, if this does happen, look for the link that says "View Table" and click on that to get to the data.

IRSA IPAC defaults to calling the ascii output .tbl files.

To save that data is browser dependent, you need to save it to disc as _text only_, so only use that choice in your browser of preference. Call it anything you want.

You can either edit out the top lines, you only need the lines with numbers in columns, or you can leave them there and ignore them, Guide shouldn't parse any lines that don't have RA and Dec info in the appropriate columns.

Rename the file to wise.dat and save it in your Guide 8 directory.

For future downloads you will save such files as whatever name you wish, and add them to the bottom of the wise.dat file by inserting them into it in a text editor, or you can have a new wise.dat every time if you don't need to keep past data. Personal choice.

Of course, you need a tdf to display the data.

Here it is :-

file WISE.dat
title WISE Preliminary Source Catalogue
RA H 2 9
units0 -2
de d 14 9
~b 4 1 WISE Source\n\n
~r 2 9 RA 2000 : %R +/- %[28,5]\n
~r 14 9 Dec2000 : %D +/- %[37,5]\n\n
~r 2 9 RA %s DE %[14,9] degrees\n\n
~b 58 6 3.4 micron mag %s +/- %[69,5]\n
~b 76 6 4.6 micron mag %s +/- %[87,5]\n
~b 94 6 12 micron mag %s +/- %[105,5]\n
~b112 6 22 micron mag %s +/- %[123,5]\n
~r 14 9 \n^IMAGE//xhttp://irsa.ipac.caltech.edu/applications/wise/#id=Hydra_wise_wise_1&DoSearch=true&subsize=0.033&band=1,2,3,4&optLevel=3a&UserTargetWorldPt=%[2,9]%%3B%s%%3BEQ_J2000
~r 4 1 &projectId=wise&searchName=wise_1^\n

sort 0
epoch 2000
type sC1c66ff;m13,13;l-13,15;l3,-13;l13,13
goto spaces
goto case
label spaces
field 0.00 10.00
shown 5
end

this needs cutting and pasting into a text editor and saving as WISE.TDF in the Guide Directory whence it will plot orange triangles at one degree fields or less, once you run Guide again.

Help and more info give position and the magnitudes in each of the 3.4, 4.6, 12 and 22 micron passbands.

Not much use to most, but here's the fun bit.

The line starting ~r 14 9 \n^IMAGE (this is the space layout for that line if it gets truncated in the email, r one space 14 three spaces 9 one space \n^ etc) and ending in J2000 is all one line. The %3B means semicolon in HTML code, as using ; in Guide truncates the url from that point. The %%3B means the second % is a %, ie real, if you put just %3B Guide looks for a TDF command called %3, which doesn't exist, and also nukes the ; coding. The second line starting ~r 4 1 is needed because in my version of Guide if one of these url lines is too long in a tdf it crashes, as there is a 200 character limit per line.

Those two lines make one url which is shown in More Info as the red underlined word 'IMAGE', and here's the example output from our randomly chosen position if it was clicked upon for that object :-

<http://irsa.ipac.caltech.edu/applications/wise/#id=Hydra_wise_wise_1&DoSearch=true&subsize=0.167&band=1,2,3,4&optLevel=3a&UserTargetWorldPt=300.22729%3B23.09604%3BEQ_J2000&projectId=wise&searchName=wise_1>

this url is all one line and has a five arcminute size (the subsize=0.167 bit, notice subsize is in degrees).

This is the WISE image server. You may have seen publicity releases of 3 colour images from WISE. If you look at the image top left on that page you will see it defaults to an IRAS image, click the TAB for that image that says 3 colour and you will get a 3 colour WISE image. A bit dull for the example I've chosen here. Let's try this one instead :-

<http://irsa.ipac.caltech.edu/applications/wise/#id=Hydra_wise_wise_1&DoSearch=true&subsize=0.2&band=1,2,3,4&optLevel=3a&UserTargetWorldPt=92.32318%3B20.65997%3BEQ_J2000&projectId=wise&searchName=wise_1>

(all one line url) which is the field for this image currently featured here :-

http://wise.ssl.berkeley.edu/

Well, it's not as good in 3 colour as their highly processed one, but if you press the little red and green interlocking square icon to top right of the 3 colour picture you get the image popped up, and a little set of tools for manipulating the image, including zoom, and immediately to the right of the two zoom icons two 'background image stretch' icons, where you can play with the colours, one globally (linear stretch, logarithmic stretch etc), t'other in detail, separately for each of 'red', 'green' and 'blue'. For instance try 'histogram equalisation' instead of the default linear for each colour. Nearly always better than linear or logarithmic no matter what image or application you are using, at least aesthetically.

And that's more or less it really.

Cheers

John


IRSA IPAC DATA EASY ACCESS ASIDE :-

Universal Access to IRSA IPAC DATA

In the above GSC22.TDF modification an url was used

http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-query?spatial=Cone&radius=600&catalog=wise_prelim_p3as_psd&outfmt=1&selcols=ra,dec,w1mpro,w1sigmpro,w2mpro,w2sigmpro,w3mpro,w3sigmpro,w4mpro,w4sigmpro&objstr=%[3,9]+%[15,9]

the %[3,9]+%[15,9] was tdf code for RA and Dec in this data. If in decimal degrees, that's fine,

objstr=123.4567 -89.0123

if in sexagesimal it has to be of the format objstr=01h23m45.67s +89d01m23.4s, including the space.

most of the other stuff in the url is just to ensure only selected columns are returned.

But the default output format will return all the relevant columns, just extra ones as well, which in this instance I didn't want. However, the default output is usually quite serviceable, eg :-

<http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-query?spatial=Cone&radius=600&catalog=wise_prelim_p3as_psd&objstr=92.323 +20.660>

returns sources in WISE for around 5 arcmins radius near NGC 2174. Notice this one leads to a webpage and you have to click on the "View Table" Link next to the plot of the sources to get the ascii table of "View Full Table" or "Download Table" links, just eyeball the html table at bottom of page.

Anyway.

This is universal for IRSA IPAC access

http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-query?spatial=Cone&radius={SIZE}&catalog={CATNAME}&objstr={RA} {DEC}

is the generic format.

{SIZE} is replaced with the search radius in arcsecs required.

{RA} and {DEC} are replaced with either decimal degrees or sexagesimal positions in the above noted format.

and {CATNAME} is replaced with the catalogue name of choice as per this list :-

http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-scan?mode=xml

for instance, first on the list, 2MASS All Sky Point Source catalogue, the above invocation URL is used with size, ra, and dec replaced appropriately, and if you look at the last mentioned URL that shows the list you can find the CATNAME for this catalogue, it is in the row called catname and is

fp_psc

so

<http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-query?spatial=Cone&radius=600&catalog=fp_psc&objstr=92.323 +20.660>

will give you the same area and position, but for 2MASS data

<http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-query?spatial=Cone&radius=600&catalog=usno_b1&objstr=92.323 +20.660>

will give you the USNO B1.0 data.

All will have full headers so you know which column is which, and can be imported wherever, or used in Guide via a dedicated TDF.

Most of these are in VizieR, and downloadable via Guide anyway (eg usno b, ucac3, akari, ppmxl, 2mass), some aren't. Sometimes VizieR is down, sometimes the mirrors are still working.

But the IRSA IPAC server will get you astrometric and infrared photometric data whenever you wish it, in a readily usable way. Remember, a cone search can be object specific is you make it small enough, too.