# Data table for comparison of JWST photometric sensitivity to other observatories. # v1.4, 10/2014, by Jane Rigby. # If you have comments or questions, please write to Jane.R.Rigby@nasa.gov # Columns are: # (1) name of filter and/or band # (2) wavelength (micron) # (3) limiting point source flux density (Jy) that can be detected at SNR=10 in 10^4 s. # (4) Code for instrument/observatory. 0=NIRSpec, 1=NIRCam, 2=MIRI, 4=HST, 5=WISE, 6=Spitzer, 10=gemini, 11=herschel, 12=sofia, # 13=alma(cycle0), 14=alma(finished), 15=VLA, 16=EVLA # (5) Reference for the sensitivity. For JWST, the requirement document is given. For other observatories, # the calculation method is given. # #instr wave(um) SNR10in10^4sJy code reference # # JWST high-level requirements for NIRCam: #NIRCAM 2.0 11.4E-9 1 ISIM-153 requirement #NIRCAM 3.5 13.8E-9 1 ISIM-153 requirement # JWST instrument-level requirements for NIRCam: F070W 0.70 20.9E-9 1 NRC-57, Sensitivity req in Nircam Specification F090W 0.90 14.3E-9 1 NRC-57, Sensitivity req in Nircam Specification F115W 1.15 11.8E-9 1 NRC-57, Sensitivity req in Nircam Specification F150W 1.50 11.2E-9 1 NRC-57, Sensitivity req in Nircam Specification F200W 2.00 11.4E-9 1 NRC-57, Sensitivity req in Nircam Specification F277W 2.77 12.3E-9 1 NRC-57, Sensitivity req in Nircam Specification F356W 3.56 13.8E-9 1 NRC-57, Sensitivity req in Nircam Specification F444W 4.44 24.5E-9 1 NRC-57, Sensitivity req in Nircam Specification # # JWST MIRI MIRI 5.6 0.2E-6 2 Appendix C of the MIRI Functional Requirements Document (JWST-RQMT-002063) MIRI 7.7 0.28E-6 2 Appendix C of JWST-RQMT-002063 MIRI 10.0 0.7E-6 2 Appendix C of JWST-RQMT-002063 MIRI 10.0 700.0E-9 2 ISIM-153 requirement #narrowband MIRI 11.3 1.8E-6 2 Appendix C of JWST-RQMT-002063 # cluttered up plot, so commented out MIRI 12.8 1.4E-6 2 Appendix C of JWST-RQMT-002063 MIRI 15.0 2.1E-6 2 Appendix C of JWST-RQMT-002063 MIRI 18.0 4.3E-6 2 Appendix C of JWST-RQMT-002063 MIRI 21.0 8.6E-6 2 Appendix C of JWST-RQMT-002063 MIRI 21.0 8.7E-6 2 ISIM-153 requirement MIRI 25.5 29E-6 2 Appendix C of JWST-RQMT-002063 # # JWST NIRSpec nirspec 3.0 1.32E-7 0 ISIM-153 requirement; NSFR-10 in NIRSpec Functional Requirements Document (JWST-RQMT-002060) # # # Spitzer IRAC 3.5 0.6E-6 6 SENSPET (Spitzer exposure time calculator); near confusion limit IRAC 4.5 1.2E-6 6 SENSPET; near confusion limit IRAC 5.8 8E-6 6 SENSPET IRAC 8.0 9.8E-6 6 SENSPET MIPS 24.0 112E-6 6 Dole et al. 2004 confusion limit, scaling from SNR=5 MIPS 70.0 6E-3 6 Dole et al. 2004 confusion limit, scaling from SNR=5 MIPS 160.0 80E-3 6 Dole et al. 2004 confusion limit, scaling from SNR=5 # # Hubble WFC3 0.606 1.5E-8 4 Same for ACS & WFC3; Inst.Hand, Tab6.10, scaled WFC3 0.814 3.2E-8 4 WFC3-UVIS ACS 0.814 2.5E-8 4 ACS WFC3 1.1 2.6E-8 4 WFC3 Inst Hand, Tab 7.10, scaled as in notes WFC3 1.6 5.0E-8 4 WFC3 Inst Hand, Tab 7.10, scaled as in notes #NIC3 1.60 1.95E-7 4 Nicmos Nic3, Nicmos ETC, flat in fnu spectrum, r=0.5" circular extraction # above commented out since WFC3 is superior at 1.6 um NIC3 1.75 6.5E-7 4 Nicmos Nic3, Nicmos ETC, flat in fnu spectrum, r=0.5" circular extraction # # It's not fair to put WISE limiting fluxes on this plot, since WISE is shallow and all-sky, not deep and # pencil-beam. But, in case you want to compare to WISE, here are the SNR=10 limits (scaled from SNR=5 WISE 3.35 0.16E-3 5 Wright et al. 2010 ApJ WISE 4.60 0.22E-3 5 Wright et al. 2010 ApJ WISE 11.56 2E-3 5 Wright et al. 2010 ApJ WISE 22.09 12E-3 5 Wright et al. 2010 ApJ # Expected SOFIA limits: FLITECAM 1.2 6.00E-06 12 sofia flitecam website, http://www.sofia.usra.edu/Science/instruments/instruments_flitecam.html, scaled to 10^4s, SNR=10 FLITECAM 1.7 7.50E-06 12 FLITECAM 2.2 6.75E-06 12 FLITECAM 2.4 3.75E-06 12 FLITECAM 3.2 1.35E-05 12 FLITECAM 3.8 7.50E-05 12 FLITECAM 4.7 3.75E-04 12 FORCAST 6.5 0.06 12 # scaling from http://www.sofia.usra.edu/Science/instruments/instruments_forcast.html FORCAST 20 0.038 12 FORCAST 25 0.071 12 # GEMINI NIRI GMOS-g' 0.475 1.07E-07 10 from ETC GMOS-r' 0.630 1.60E-07 10 GMOS-i' 0.780 2.30E-07 10 GMOS-z' 0.950 5.30E-07 10 GMOS-Y 1.01 2.00E-06 10 NIRI 1.25 1.1E-06 10 http://www.gemini.edu/sciops/instruments/niri/itc-sensitivity-and-overheads?q=node/10088, scaled to sn=10, 10^4s NIRI 1.65 1.7E-06 10 NIRI 2.20 9.0E-07 10 NIRI 3.76 5.6E-05 10 NIRI 4.68 4.4E-04 10 # # #Extending comparison beyond the wavelength range of JWST, for general "place of JWST among great observatories" plots. Herschel-PACS 70. 6E-3 11 # PACS_flyer_2May2010.pdf Herschel-PACS 100. 6E-3 11 # PACS_flyer_2May2010.pdf Herschel-PACS 160. 12E-3 11 # PACS_flyer_2May2010.pdf. Confusion is not that important: 1.4 mJy 1 sig. Herschel-SPIRE 250. 6E-3 11 # From Herschel-Spot. Scaled 1sig->SNR=10. This includes shot, instrumental noise, # but dominated by confusion, and therefore limits are close to the SPIRE confusion # limits as measured by Nguyen et al. 2010. Herschel-SPIRE 350. 8.3E-2 11 # Ditto Herschel-SPIRE 500. 10.3E-2 11 # Ditto # # ALMA in Cycle 0 band3 4.0E3 0.17E-3 13 # https://almascience.nrao.edu/call-for-proposals/capabilities, scaled 1hr->10^4s, SNR=5 to SNR=10 band6 1.7E3 0.24E-3 13 band7 1.16E3 0.44E-3 13 band9 590. 3.84E-3 13 # ALMA when finished # http://almascience.eso.org/call-for-proposals/sensitivity-calculator, upped to 50x12m, 12x7m antennae band3 4E3 5E-5 14 band4 2.85E3 8E-5 14 band6 1.7E3 8E-5 14 band7 1.16E3 1.4E-4 14 band8 1160 1.4E-4 14 band9 590 1.3E-3 14 band10 470 3.1E-3 14 #multiply tabulated sensitivites x21 to get 10^4s, SNR=10, then 1E-3 to get to Jy VLA 400E4. 0.4 15 # http://www.vla.nrao.edu/astro/guides/vlas/current/node11.html, scaled SNR=1->SNR=10, 12 hr to 10^4s VLA 90E4. 3.9E-3 15 VLA 20E4 1.5E-4 15 VLA 6.0E4 1.5E-4 15 VLA 3.6E4 1.2E-4 15 VLA 1.3E4 2.7E-4 15 VLA 0.7E4 6.7E-4 15 # EVLA 8E3 32E-6 16 http://www.vla.nrao.edu/astro/guides/vlas/current/node11.html, scaled SNR=1->SNR=10, 9 hr to 10^4s EVLA 1.1E4 15E-6 16 EVLA 1.8E4 11E-6 16 EVLA 6.7E4 9E-6 16 EVLA 2.7E5 29E-6 16 # Further description of how comparison sensitivities were calculated: # # MIPS/Spitzer hits the 24um confusion well before 10^4 s. # Therefore, to get a relevant 24um Spitzer performance here, I took # the SNR=5 SDC value of 56 uJy from Dole et al. 2004, and simply # multiplied by 2 to get SNR=10. In detail this isn't quite right, # but should be close. # # As for IRAC/Spitzer, Fazio et al. 2004 reported that 5.8, 8 micron bands weren't # confused even in 15,000s -- so it's safe to use SENSPET. 3.5, 4.5 micron bands # start having confusion after 2000s (Fazio et al. 2004), which means the SENSPET # values are probably a bit optimistic. For cross-check, Krick et al 2009 reports # 3 sigma 95% completeness limits of 0.2, 0.17 microJy in ch1,2 for a 36ks exposure; # to 10 sigma that would be 0.7, 0.6 muJy. This confirms that the SENSPET values # are a bit optimistic. Still, let's use them here, to be maximally fair to Spitzer. # # HST: WFC3-IR Instrument Handbook, table 7.10 gives limiting-magnitudes, SNR=10, # 1 hr and 10 hr exposure. For both 1 and 10 hr limits, I converted from mAB # to Jy, and scaled to 10^4s. The resulting scaled limits agree to 5%. # Repeated for WFC3-UVIS and ACS. # # WISE: Wright et al 2010 ApJ, Section 3, has SNR=5, w/ confusion. # D. Benford (priv. comm.) warns that these values are skewed high by the Galactic plane; # WISE does better in the galactic poles. # # For GEMINI GMOS, I used the ETC, 10^4s, SNR=10, spectrum flat in fnu, and the passbands above, and # iterated to find the limiting flux density. For GEMINI NIRI, I used the quoted sensitivities at # http://www.gemini.edu/sciops/instruments/niri/itc-sensitivity-and-overheads?q=node/10088, # and scaled to SNR=10, 10^4s. # Data tabulated by Jane Rigby. Please email Jane.R.Rigby@nasa.gov if you have comments or suggestions.