NearIR properties of Spitzer sources

1
Near-IR properties of Spitzer sources
Eduardo Gonzalez-Solares, Nic Walton (IoA,
University of Cambridge, UK) Anita
Richards (Jodrell Bank, University of Manchester,
UK) Jonathan Tedds (University of Leicester,
UK) AstroGrid Collaboration
2
Topics

• Data UKIDSS, SWIRE, WFS, SDSS
• Near-IR colours of Spitzer sources
• Optically blank fields
• Using Astrogrid and the VO

3
The UKIRT Infrared Deep Sky Survey (see Dye et
al. 2006 Early Data Release Paper)

• Survey being carried out using WFCAM on UKIRT
• Programme of 5 surveys using ZYJHK
• Different areas and depths
• Shallow surveys GCS (K18.6 1067) , GPS (K19
  1868), LAS (K18.2 4028)
• Deep Surveys DXS(K21 35) , UDS (K22.8 0.77)
• Seeing 0.6 to 1.2

4
WFCAM Surveys Distribution on sky and survey
progress
image from CASU web site http//www.ast.cam.ac.uk/
vdfs
5
WFCAM Surveys Data Volume Comparison
Values from Simon Hodgkin (IoA)
6
UKIDSS Surveys Deep extragalactic survey (DXS)

• J and K over 35 sq. deg.
• Magnitude limits
• J 22.5
• K 21.0
• Seeing 1.1
• Areas
• ELAIS N1, Lockman
• VIMOS 4, XMMLSS

7
UKIDSS DXS vs 2MASS Depth Comparison
8
Spitzer Data The Spitzer Wide Area Extragalactic
Survey (SWIRE)

• SWIRE (Lonsdale et al 2005) and UKIDSS DXS well
  matched in terms of area
• Provides photometry in 4 IRAC 3 MIPS bands
• Ancillary optical photometry from the Wide Field
  Survey (McMahon et al 2004) in ugriz bands.
• Also SDSS photometry and spectra (not complete in
  all regions)

9
Mid-IR Colour Diagnostics Point-like objects and
QSO
Efficient selection of QSO using mid-IR
colours (e.g. Lacy et al. 2004)
Enhanced using optical photometry (SDSS) Richards
et al 2006
Near-IR helps for faint optical sources and
for blank fields
10
Near-IR Colours of Spitzer sources
models from Polleta et al 2006
11
Optical blank fields Near-IR detections
12
Optical blank fields Near-IR detections

• Point-like morphology
• mid-IR diagnostics of AGN
• Faint in J magnitude
• Red in J-K gt 1.0
• Some examples...

13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
The advantages of the VO AstroGrid

• Accessing multiwavelength data easier
• Do not need to access different interfaces,
  register

17
(No Transcript)
18
The advantages of the VO AstroGrid

• Accessing multiwavelength data easier
• Do not need to access different interfaces,
  register
• Data access from one single entry point
• Able to build workflows i.e. pieces of code which
  run on the server and are reusable

19
SDSS Query
Table Crossmatch
20
SWIRE Query
Table Crossmatch
21
Building a Query The AstroGrid query builder
SELECT FROM swire_en1 AS a WHERE a.ra BETWEEN
242 AND 243.6 AND a.dec BETWEEN 54.1 AND 55.1
AND a.flux_ap_36 gt 10
SELECT a.ra, a.dec, a.u, a.g, a.r, a.i, a.z,
a.err_u, a.err_g, a.err_r, a.err_i, a.err_z,
a.type FROM PhotoObj AS a WHERE a.ra BETWEEN 242
AND 243.6 AND a.dec BETWEEN 54.1 AND 55.1 AND
22
Building a query AstroGrid Query Builder
Table Description
Selected table
Table Columns
Query being built
Dialog to insert selected columns into
selected section of the query
List of tables in the database
23
The advantages and the VO AstroGrid

• Accessing multiwavelength data easier
• Do not need to access different interfaces,
  register
• Data access from one single entry point
• Able to build workflows i.e. pieces of code which
  run on the server and are reusable
• Tools to analyse the returned data
• Different tools which share standards on how to
  interoperate

24
Interactive source analysis Graphical selection
of sources
25
Interactive source analysis Data display
26
Interactive source analysis Access to external
services (e.g. IPAC postage stamps)
27
The advantages of the VO AstroGrid

• Accessing multiwavelength data easier
• Do not need to access different interfaces,
  register
• Data access from one single entry point
• Able to build workflows i.e. pieces of code which
  run on the server and are reusable
• Tools to analyse the returned data
• Different tools which share standards on how to
  interoperate
• All data search and access from one single window

28
(No Transcript)
29
Summary

• Near-IR helps distinguish QSO at faint optical
  magnitudes
• Optical blank fields faint in J and red in J-K
• AstroGrid helps to carry out the analysis in one
  field and trivially extend to others
• Tools to interactively look at results as well as
  run intensive non interactive tasks in the server
• All data at the reach of one click