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Systematic Detections of Starbursting Dwarf Galaxies. Michael Maseda MPIA. Photometric Selection. Detection of Sources. Identify all point sources in grism image Mask 0 th order objects with H F140W < 22.5 Create extraction box in direct image around candidates from grism image
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Systematic Detections of Starbursting Dwarf Galaxies Michael Maseda MPIA
Detection of Sources • Identify all point sources in grism image • Mask 0th order objects with HF140W < 22.5 • Create extraction box in direct image around candidates from grism image • Match sources within that box to objects in master catalog • Visually inspect the extracted spectrum
Detection of Sources • Identify all point sources in grism image • Mask 0th order objects with HF140W < 22.5 • Create extraction box in direct image around candidates from grism image • Match sources within that box to objects in master catalog • Visually inspect the extracted spectrum
Detection of Sources • Identify all point sources in grism image • Mask 0th order objects with HF140W < 22.5 • Create extraction box in direct image around candidates from grism image • Match sources within that box to objects in master catalog • Visually inspect the extracted spectrum
Detection of Sources • Identify all point sources in grism image • Mask 0th order objects with HF140W < 22.5 • Create extraction box in direct image around candidates from grism image • Match sources within that box to objects in master catalog • Visually inspect the extracted spectrum
Grism Direct
Detection of Sources • Identify all point sources in grism image • Mask 0th order objects with HF140W < 22.5 • Create extraction box in direct image around candidates from grism image • Match sources within that box to objects in master catalog • Visually inspect the extracted spectrum
Detection of Sources • Identify all point sources in grism image • Mask 0th order objects with HF140W < 22.5 • Create extraction box in direct image around candidates from grism image • Match sources within that box to objects in master catalog • Visually inspect the extracted spectrum
Sanity Check • Arjen found two objects in the ERS pointing • I blindly found his two, plus an additional object that is possibly an Hα source at z=1 • Broad-band photometry confirmed the excess in the J-band
Advantages • Can be used to find these objects at different redshifts and at lower S/N • Not forced to use the 3D-HST catalog • Can find objects fainter than the HF140W < 25 limit • Simple enough to be done right now!
But… • It’s not 100% automated • Current 3D-HST coverage is missing the pointings that Arjen used in UDS and GOODS-S • Only have the single ERS pointing as a test
Conclusion • Our small test showed promising results • Can we assume that this is enough and continue with other fields? • Or we can look for high-EW objects in the 3D-HST catalog (in-progress for GOODS-S 27) • Eventually want to be able to make detections deep into the noise