HyperatlasCoregistered Federated Imagery

Roy WilliamsBruce BerrimanGeorge DjorgovskiJohn GoodReagan Moore

Caltech CACRCaltech IPAC

Caltech AstronomyCaltech IPAC

San Diego Supercomputer Center

Image Federation

Multispectral Imagery

Crab Nebula.3 channels: radio in red. optical in green, and X-ray in blue.

Moffet Field California. 224 channels from 400 nm to 2500 nm

2MASS-SDSS fusion

Red at 1.2 um (2MASS J), Green at 0.75 um (SDSS i), Blue at 0.47 um (SDSS g).

Image Federation

detection

Stacking allows detection of faint sources. A 1-sigma detection in each of many bands becomes a 3-sigma detection.

Images of the same galaxy taken several days apart are automatically subtracted from one another, and remaining bright spots may be supernova candidates. (NEAT project)

Image subtraction allows detection of narrow-line features that are not also wide-band (eg Hα but not R-band)

Multiwavelength Sky

• Sociology of EM spectrum• “Xray astronomy”, “Radio astronomy”

• Essentially multiwavelength objects• Can only be seen in different bands• Quasars discovered by Radio/Optical fusion• Gamma ray bursts in Gamma/optical

Time Federation

• Palomar-Quest survey• 50 Gbyte/night to Caltech/Yale• Searching for transients

– asteroids, plutinos

– catalysmic variables

– lensing events (MACHO)

– cataclysmic galaxies

– quasar transients

– Deep catalogs– Average sky– Maximum sky– Time correlated sky (deep periodics)

Atlasmaker:Principle Components

SDSS (5 channel) SDSS+2MASS (8 channel)

ExampleNGC 4125 at 50 Mpc

2MA

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fusion

Images and Pages

Image• Big data

Page• Map: sphere → plane• FITS-WCS header• small data

An atlas is a collection of pagesHyperatlas is an attempt to standardize atlases

HyperatlasStandard naming for atlases and pages

TM-5-SIN-20Page 1589

Standard Scales:scale s means 220-s arcseconds per pixel

SIN projection

TAN projection

TM-5 layout

HV-4 layout

Standard Projections

StandardLayout

Hyperatlas is a Service

All Pages: <baseURL>/getChart?atlas=TM-5-SIN-200 2.77777778E-4 'RA---SIN’ 'DEC--SIN' 0.0 -90.01 2.77777778E-4 'RA---SIN‘ 'DEC--SIN' 0.0 -85.02 2.77777778E-4 'RA---SIN‘ 'DEC--SIN' 36.0 -85.0...17312.77777778E-4 'RA---SIN‘ 'DEC--SIN' 288.0 85.017322.77777778E-4 'RA---SIN‘ 'DEC--SIN' 324.0 85.017332.77777778E-4 'RA---SIN‘ 'DEC--SIN' 0.0 90.0

Best Page: <baseURL>/getChart?atlas=TM-5-SIN-20&RA=182&Dec=621604 2.77777778E-4 'RA---SIN‘ 'DEC--SIN' 184.61538 60.0

Numbered Page: <baseURL>/getChart?atlas=TM-5-SIN-20&page=16041604 2.77777778E-4 'RA---SIN' 'DEC--SIN' 184.61538 60.0

ImplementationsbaseURL = http://mercury.cacr.caltech.edu:8080/hyperatlasbaseURL = http://virtualsky.org/servlet

Various TM Atlases

20 degree

10 degree

5 degree

Various HV Atlases

Google Sky

Renders all data to single CAR (Mercator) projection

-- Good for Jpeg, not for FITS…..

Hyperatlas Services

Questions:Who does resampling of images and why?What science is in images that is not in catalogs?

Hyperatlas Serviceshttp:nvo.caltech.edu:8080/hyperatlas

Transparent Code

int ndec = 1 + (int)(180/delta + 0.5);double ddec = 180.0/(ndec-1);int nra;double dra;for(int i=0; i<ndec; i++){

dec = -90 + i*ddec;

// This prevents gaps in the rings near the polsif(dec<0) dech=dec+0.5*ddec;else dech=dec-0.5*ddec;

nra = (int)((360/delta) * Math.cos(dech*Math.PI/180)) + 1;

if(i==0 || i==ndec-1) nra=1;dra = 360.0/nra;for(int j=0; j<nra; j++){

v = new Vector3d(dra*j, dec);points.addElement(v);

}}

Projects

• 2MASS hyperatlas at SDSC complete• SDSS DR5 starting• Palomar-Quest also building HA• Nesssi services make HA tiles