notes from meeting with Oxonians

LSD 101 for HWR

Notes from an 'idiot's tutorial' on how to get to LSD data base tools
on MPIA computers, and then link this to pythoning... (E. Schlafly --> HWR)

As of July 2013 the PS1 stuff is migrating to aida41233; so: ssh -Y aida41233

then: 

> source /disk/LSD/LSD/lsd_environment_a41233_2
> ipython --pylab

within python


plot(arange(10))  % test whether plotting windows

from lsd import bounds  %
import util_efs_pub
ob=util_efs_pub.query_lsd('select * from ucal_magsqw',bounds=bounds.beam(150.,50.,1.))
% the syntax of that query should be like sql; in essence get "everything" within 1 degree of (150,50)
len(ob)
ob.dtype %take a look at what's in the table
m = numpy.sum(ob['namg_ok']>0,axis=1) >=3
m = numpy.sum(ob['nmag_ok']>0,axis=1) >=3  % pick out those object with good detection in 3 bands
clf(); plot(ob['ra'][m], ab['dec'][m], ',')  % make a plot
clf(); plot(ob['ra'][m], ob['dec'][m], ',')
clf() ; plot(ob['mean'][:,0]-ob['mean'][:,1],ob['mean'][:,0], ',')   % make a CMD
ob.dtype

%save first_lsd_steps 1-18   % that saves the session
ob=util_efs_pub.query_lsd('select * from ucal_magsqw , sdss(matchedto=ucal_magsqw)',bounds=bounds.beam(150.,50.,1.))  % cross-matched catalog
ob_stack=util_efs_pub.query_lsd('select * from stack , sdss(matchedto=stack)',bounds=bounds.beam(150.,50.,1.))   % query stacked catalog
ob_stack=util_efs_pub.query_lsd('select * from ps1_det , sdss(matchedto=ps1_det)',bounds=bounds.beam(150.,50.,1.))
ob_stack.dtype
ob_ps1_det=util_efs_pub.query_lsd('select * from ps1_det , sdss(matchedto=ps1_det)',bounds=bounds.beam(150.,50.,1.))


Issues: there is no single data base that has everything; e.g. to get proper motions,
 one has to talk to Bertrand where this information is....


subsequent e-mail from Eddie

The database that Bertrand has made with Gene's proper motions is in:
/a41217d5/LSD/PS1/tpifeb13
That means if your LSD_DB includes /a41217d5/LSD/PS1
then you can get at the proper motions via
select * from tpifeb13
or
select * from ucal_magsqw, tpifeb13(matchedto=tpifeb13) ...
and things should work.

MilkyWay Kinematics with Astrometry from PS1 (and SDSS)

Some thoughts on how to go about getting the best proper motions in the ICR from PS1

Stream finding & stream follow-up with PS1

I might want to get back into the stream analysis business again. Variety of angles: it's part of the SFB 881 project; I would like to see how well proper motion cleaning works for finding stellar halo streams traced by giants; a good test case to combine proper motions between PS1 & SDSS.

Possible starting point: the Pisces stream, recently found by Martin et al (http://arxiv.org/pdf/1302.2155v1.pdf). This stream appears to be traced in giants,
at a goodly distance of 35 kpc. I wonder whether one can do both a photometric metallicity "cleaning" of the stream, using ugr [XX will look at the metallicity diagnostic of old giants in the
ugr plane]; and the contaminant MS stars at g-r=0.6 and r<19.5 should be at ~3 kpc, where their
dispersion should be ~>60 km/s, hence detectable by proper motions...
This might lead me to re-open the questio of optimal filtering a la Koposov et al 2010.

PS1 and astrometry:
Bertrand G. took the PS1 pipeline proper motions and did the mean proper motions of known SDSS quasars in 4x4deg fields. The mean proper motion (reflecting the deviation from an inertial frame),
showed a smooth pattern with an amplitude of ~10 mas/yr.

He will take half the QSO sample correct the other half and see what happens.
That seems to imply that the calibration to the QSO's should work well.
That, in turn, bring new motivation to identify all PS1 quasars by a mix of WISE colors
and variability. In particular, we will need to look at the regions of considerable extinction
at low latitude.  So, let's find quasars at |b|<15, to map the Galaxy.

Age vs [Fe/H] in the solar neighborhood

We should check at some point that we get the age distribution,
at a given metallicity, in the solar neighborhood (e.g. Schönrich & Binney)
right in the Stinson et al simulations.

1st GES science meeting

Had some interesting conversations at the GES meeting:

-- immediate things to do:
    * get access to the Edinburgh archive with Michelle and get the FGK stars out
    * try to cross-match this with PS1 photometer
    * distances should not come from only log_g; photometry has to come in.

--  mid-run:
     * get best distances
     * cross-correlate abundances GES-SDSS to get them at the same footing
     * we need to get the best proper motions!!