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Sahar Allam, Perry Gee, Yeong Loh, Ivanio Puerari, Douglas Tucker. Finding and Exploring Merging Pairs of Galaxies in 2MASS using the NVO. Goals. Use the NVO to identify (relatively) isolated merging pairs of galaxies from the 2MASS eXtended Source Catalog (XSC)
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Sahar Allam, Perry Gee, Yeong Loh, Ivanio Puerari, Douglas Tucker Finding and Exploring Merging Pairs of Galaxies in 2MASS using the NVO
Goals • Use the NVO to identify (relatively) isolated merging pairs of galaxies from the 2MASS eXtended Source Catalog (XSC) • Perform exploratory research into the properties of the pairs and their member galaxies (NIR, Optical, Radio, X-Ray) • Existence of hot or cold gas surrounding individual pairs • Star Formation/AGN Properties (e.g., like in Chris's and Simon's talks)
i D>20xs s<4di j • Modified Karachentsev Criteria Finding Merging Pairs in 2MASS • Used Open Sky Query to download 125 sq deg of data (ra, dec, J, H, Ks, rext, flags) from the photoXSC table in the TWOMASS database
The Catalog (SDSS astrotools) • 91 candidate merging pairs in 125 sq deg • some are garbage (~10%) +1.25° - DEC -1.25° - 0° 50° RA
Image Gallery (NIR & Radio/SkyView) • image: 2MASS Ks; red contours: FIRST
Photometric Properties (TOPCAT) SDSS g-r vs u-g 2MASS J-H vs SDSS i-z g-r J-H u-g i-z 2MASS H-Ks vs J-H GALEX nuv – fuv H-Ks fuv mag J-H
18 Number 0 0.00 0.10 0.20 0.30 redshift Redshifts (matches with SDSS)
Spectra (SDSS) Pair 8 z=0.0631 8-952 8-951 dv ~ 150 km/s z=0.0636
Spectral Classfication (Open Sky Query) SELECT t.ra, t.dec,t.pairid,t.objid,t.matchobjid, s.specobjid, s.z,s.zerr,s.zWarning, s.velDisp, s.velDispErr, s.specClass, s.eClass, s.plate,s.fiberID, l.height, l.sigma, l.wave,l.restWave,l.z FROM SDSSDR3:PhotoPrimary o, SDSSDR3:SpecObj s,SDSSDR3:SpecLine l, Mydata:MergePair t WHERE o.specobjid = s.specobjid and l.specobjid = s.specobjid and XMATCH(o, t) < 3.5 and s.zWarning=0 and l.restWave between 5008.2 and 5008.3 ORDER BY t.pairid
Spectral Classification ( TOPCAT/IDL) AGN log [O II] / [Hbeta] Starbursts log [N II] / [Halpha]
Future • AstroGRID or other GRID resources to do full 2MASS XSC (all-sky) • Move from web-based to command-line-based queries • NVO Research Initiative proposal? (Oct 1!)
Tools • Open Sky Query • download 2MASS XSC data • match 2MASS merging pair galaxies with SDSS, FIRST, XMM, ROSAT, and GALEX catalogs • Topcat and VOPlot • analyze photo. and spectro. properties of pairs • SkyView • obtain 2MASS, FIRST, and X-ray images of pairs • SDSS SkyServer • obtain optical images of pairs