The UKIDSS Galactic Plane Survey

1
The UKIDSS Galactic Plane Survey
Phil Lucas University of
Hertfordshire Andy Adamson, Chris Davis
JAC Andy Longmore
Edinburgh ATC Reba Bandyopadhyay
U Florida Anja Schroeder
U Leicester Richard de Grijs
U Sheffield Melvin Hoare
U Leeds Michael Smith, Sharon
Mitchison U Kent Tom Maccarone U
Southampton ESO-Garching 17 December
2007 Group paper Lucas et al., MNRAS submitted

astro-ph/0712.0100
2

• Outline
• Overview of the UKIDSS GPS and Galactic Surveys
• Populations as a fn. of Galactic Coordinates
• Identifying and classifying protostars with the
  GPS/GLIMPSE cross match
• Searches for new clusters in the GPS

3
WFCAM The UKIRT Wide Field Camera

• WFCAM was constructed at the UK ATC and
  commissioned on UKIRT in April 2005.
• Project Scientist Mark Casali
• Data Reduction Cambridge Astronomical Survey
  Unit. (Mike Irwin et al.)
• SQL archive Wide Field Astronomy Unit, Edinburgh
  IfA (Nigel Hambly et al.)

4
UKIDSS GPS
DR2 DR3 DR4
5
UKIDSS GPS Progress

• EDR 15 deg2 at JHK. 58 deg2 at K
  band.
• DR1 77 deg2 at JHK. 343 deg2 at K
  band.
• 
  71 deg2 at H2 .
• DR2 236 deg2 at JHK. 657 deg2 at K
  band.
• DR3 346 deg2 at JHK. 965 deg2 at K
  band.
• Observed to 31 Oct 2007
• 550 deg2 at JHK 1320 deg2 at K band (including
  bad data).

6
UKIDSS GPS Strategy

• Original strategy (see Lawrence et al.2007, MNRAS
  379, 1599)
• 1st epoch imaging at JHK in photometric
  conditions. 2nd and 3rd epoch imaging at K band
  only after an interval of some years.
• Current strategy (see Lucas et al.2007,
  astro-ph/0712.0100)
• One epoch only at JHK in photometric conditions.
  Possible continuation of K only data after 2010.
• Things that havent changed
• 3 band data taken near simultaneously (within a
  20 minute period).
• Integration times are 80s, 80s, 40s at JHK.
• 2x2 microstepping is used to improve resolution
  -gt 0.2 pixels.
• Relaxing constraints
• Using non-photometric conditions to ensure the
  survey is finished.
• Prioritising areas near the mid-plane.

7
GPS Depth
The GPS is close to confusion limited in the
inner Galaxy. Hence it will not be possible to go
deeper until a wide field high resolution
infrared telescope is placed in space. Median
5-? depths in DR2 (Vega mags) J19.8 H19.0
K18.1 But 5-sigma (i.e. ?m0.20 mag) should
not be taken literally. The quoted errors do not
take account of blending or bad pixels. The
quoted errors do not include IPC, which means
that 5-? -gt 4-?. Even in uncrowded fields the
modal magnitudes are typically J19.4 to
19.65 H18.5 to 18.75 K17.75 to 18.0.
8
Aperture photometry in crowded fields
9
Aperture photometry in crowded fields
a) All 51780 sources (except noise b)
8183 sources from (a) with errorslt0.05 sources)
mag on each axis.
d) 2787 sources from (b) with stellar image
profiles and most reliable photometry
c) 5914 sources from (b) with stellar image
profiles and more reliable photometry
10
Milky Way Surveys coming of age
Optical INT 2.5-m. IPHAS Galactic survey,
2003-2008. VST 2.6-m. VPHAS Galactic survey
starts in 2009? Near IR UKIDSS GPS,
2005-2012. VISTA VVV, 2009-2013. Mid-IR
Spitzer GLIMPSE, GLIMPSE II, l-70 to 70, blt1,
completed. MSX, 0ltllt360, blt5, 8-21
um, 33 cm scope, completed. WISE,
NASA all sky survey satellite, 2009, 3.6, 4.5,
12, 24 um. Far-IR Spitzer MIPSGAL.
(24-70 um), 2006, covers GLIMPSE regions.
Akari all sky coverage at 50-150 um. February
2006- August 2007. Submm HERSCHEL
Hi-Gal (70-500 um), 2008-9, -60ltllt60 at
blt1. decision on this survey in January 2008.
YES!! SCUBA-2. SASSy (850 um),
l0-270, blt5, 2008-10. SCUBA-2.
JPS (450, 850 um), l0-270, blt1, 2008-10.
APEX in the South ?? Radio CORNISH 5 GHz VLA
survey, GLIMPSE-North region. 2006-07.
MMB Methanol Maser Survey at Parkes, nearing
completion. X-ray and Gamma ray INTEGRAL,
blt5, complete. GLAST, all sky, 2007-09.
ROSAT all sky, complete. XMM, CHANDRA
small surveys.
11
VISTA
12
VISTA Variables in the Via Lactea (VVV)

• VVV is a synoptic survey of the Bulge and a
  section of the southern plane.
• Area 300 sq. deg. in the Bulge and the 220 sq.
  deg in the Plane region. The Plane region covers
  GLIMPSE-South and MIPSGAL-South, broadened to
  latitudes blt2.
• Principal Aim mapping Galactic structure in 3-D
  with RR Lyraes and Cepheids.
• 109 stars, 106 variables
• Filters ZYJHKs Atlas in Year 1, with near
  simultaneous fluxes in the 5 bands.
• 80 Epochs in Kshort in Years 3 (Bulge) and 4
  (Plane) 1 Epoch per night.
• Small fields to be monitored continuously in Year
  5, permitting detection of eclipsing binaries and
  characterising short period variables.

13
Extinction Histograms in the Plane
blt0.1 60 of HK detections have A(V) lt10
4ltblt5 90 of HK detections have A(V)
lt10. Hence there is plenty of scope for work at
r, i, Z and Y.
14
(No Transcript)
15
The WFCAM Science Archive

• http//surveys.roe.ac.uk/wsa/

16
Stellar populations as a fn. of Galactic
coordinates
l,b0,0 l,b15,0
17
Stellar populations as a fn. of Galactic
coordinates(2)
l,b31,0 l,b55,1
18
Stellar populations as a fn. of Galactic
coordinates(3)
l,b15,1 l,b15,1 Besançon
19
Stellar populations as a fn. of Galactic
coordinates(2)
l,b 171, 4.75 l,b 173, 0.65
20
An IPHAS/GPS cross match
The IPHAS IDR occurred in December 2007 see
www.iphas.org
Giants (mostly K type)
A and F dwarfs
G and K dwarfs
21
Star formation in detail NGC1333
NGC1333 in Perseus Credit NOAO, C.Lada and the
Flamingos team. Kitt Peak 2.1m.
22
(No Transcript)
23
Davis, Scholz, Lucas, Smith, Adamson(MNRAS,
submitted)
24
(No Transcript)
25
Classifying YSOs with GPS and GLIMPSE data
G28.983-0.603 A cluster found in 2MASS by
Bica et al.(2003, AA 404, 223). The Spitzer
GLIMPSE 4.5 micron data allows us to separate
Class I and Class II YSOs from field stars and
Class III YSOs.
26
Near IRMid IR YSO classification(from Robert
Gutermuths thesis
27
Building a sample of star formation regions in
the GPS

• Large lists of clusters have been published by.
• 1) Bica Dutra (2003 papers)
• did a biased eyeball search of 2MASS.
• 45 of these in DR2 - 37 are obvious SFRs or parts
  of SFRs.
• 2) Mercer et al.(2005)
• did a Bayesian search of Spitzer/GLIMPSE.
• 12 of these in DR2 - 7 are obvious SFRs.
• 3) Froebrich et al.(2006)
• searched for statistical overdensities in 2MASS.
• 91 of these in DR2 - only a few are SFRs.

28
BDS 121 (d9kpc, high extinction) Numerous
unstudied clusters are turning up, eg. BDS121,
which is listed by Bica Dutra but has no
optical/ near IR literature.
29
Finding new clusters in the GPS

• We are using three methods to search the UKIDSS
  GPS for new clusters
• 1) An eyeball search of all the jpeg images
  during quality control.
• 2) A Bayesian search building on the approach of
  Mercer et al. (Samuel Lucas).
• 3) A search for clusters in the vicinity of
  methanol masers from MMB.
• Another method we will try
• 4) an unbiased Spitzer/GPS search for objects
  with the colours of YSOs.

30
A methanol maser survey (MMB) source
31
Bayesian search Expectation Maximisation (EM)
Method
For each field (i.e. each 13 arcminute WFCAM
array) do E step - determine ln(L) given
cluster parameters M step - shift the cluster
parameters in the direction of increased
likelihood. Iterate E and M steps to convergance.
Maximise the Bayesian Information Criterion
(BIC) BIC ln(L) - m ln(N) Start with 0
clusters, repeat the process with 1, 2, 3, 4
clusters.
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
A New Eyeball search tool surveys.roe.ac.uk/wsa/g
allery
Courtesy of Mike Read, WFAU
43
Images from the Interactive Gallery
44
A new Galactic globular cluster in the GPS

• D5.2 kpc, A(V)9 mag
• Contains a fairly bright XMM X-ray source.