J/ApJ/717/257 Synthetic spectra of dark stars (Zackrisson+, 2010) ================================================================================ Finding High-redshift Dark Stars with the James Webb Space Telescope Zackrisson E., Scott P., Rydberg C.-E., Iocco F., Edvardsson B., Ostlin G., Sivertsson S., Zitrin A., Broadhurst T., Gondolo P. =2010ApJ...717..257Z ================================================================================ ADC_Keywords: Models, atmosphere ; Photometry, infrared Keywords: dark ages ; reionization ; first stars ; dark matter ; galaxies: high-redshift ; stars: Population III Abstract: The first stars in the history of the Universe are likely to form in the dense central regions of {sim.to}10^5^-10^6^ M_{sun}_ cold dark matter halos at z{approx}10--50. The annihilation of dark matter particles in these environments may lead to the formation of so-called dark stars, which are predicted to be cooler, larger, more massive and potentially more long-lived than conventional population III stars. Here, we investigate the prospects of detecting high-redshift dark stars with the upcoming James Webb Space Telescope (JWST). We find that all dark stars with masses up to 10^3^ M_{sun}_ are intrinsically too faint to be detected by JWST at z above 6. However, by exploiting foreground galaxy clusters as gravitational telescopes, certain varieties of cool (T_eff_<=30000K) dark stars should be within reach at redshifts up to z{approx}10. If the lifetimes of dark stars are sufficiently long, many such objects may also congregate inside the first galaxies. We demonstrate that this could give rise to peculiar features in the integrated spectra of galaxies at high redshifts, provided that dark stars make up at least {sim.to}1% of the total stellar mass in such objects. Description: Model spectra and JWST broadband magnitudes for the 18 dark star models discussed in the paper. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file param.dat 23 18 Basic parameters for the dark star models spectra.dat 33 729465 Synthetic stellar atmosphere spectra miri.dat 102 738 JWST/MIRI magnitudes as a function of z nircam.dat 82 738 JWST/NIRCam magnitudes as a function of z -------------------------------------------------------------------------------- Byte-by-byte Description of file: param.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 5 I02 --- Model Model number 6- 14 E9.1 eV MWIMP WIMP (weakly interacting massive particles) mass 15- 23 I9 solMass MDS Dark star mass -------------------------------------------------------------------------------- Byte-by-byte Description of file: spectra.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 5 I02 --- Model Model number 7- 19 E13.6 0.1nm lambda Rest frame wavelength 21- 33 E13.6 uW/nm L.lambda Rest frame specific luminosity (in erg/s/{AA}) -------------------------------------------------------------------------------- Byte-by-byte Description of file: miri.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 5 I02 --- Model Model number 6- 12 F7.3 --- z Redshift 13- 22 F10.3 mag F560W ?=999.0 Flux in JWST/MIRI F560W filter (G1) 23- 32 F10.3 mag F770W ?=999.0 Flux in JWST/MIRI F770W filter (G1) 33- 42 F10.3 mag F1100W ?=999.0 Flux in JWST/MIRI F1100W filter (G1) 43- 52 F10.3 mag F1130W ?=999.0 Flux in JWST/MIRI F1130W filter (G1) 53- 62 F10.3 mag F1280W ?=999.0 Flux in JWST/MIRI F1280W filter (G1) 63- 72 F10.3 mag F1500W ?=999.0 Flux in JWST/MIRI F1500W filter (G1) 73- 82 F10.3 mag F1800W ?=999.0 Flux in JWST/MIRI F1800W filter (G1) 83- 92 F10.3 mag F2100W ?=999.0 Flux in JWST/MIRI F2100W filter (G1) 93-102 F10.3 mag F2550W ?=999.0 Flux in JWST/MIRI F2550W filter (G1) -------------------------------------------------------------------------------- Byte-by-byte Description of file: nircam.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 5 I02 --- Model Model number 6- 12 F7.3 --- z Redshift 13- 22 F10.3 mag F070W ?=999.0 Flux in JWST/NIRCam F070W filter (G1) 23- 32 F10.3 mag F115W ?=999.0 Flux in JWST/NIRCam F115W filter (G1) 33- 42 F10.3 mag F150W ?=999.0 Flux in JWST/NIRCam F150W filter (G1) 43- 52 F10.3 mag F200W ?=999.0 Flux in JWST/NIRCam F200W filter (G1) 53- 62 F10.3 mag F277W ?=999.0 Flux in JWST/NIRCam F277W filter (G1) 63- 72 F10.3 mag F356W ?=999.0 Flux in JWST/NIRCam F356W filter (G1) 73- 82 F10.3 mag F444W ?=999.0 Flux in JWST/NIRCam F444W filter (G1) -------------------------------------------------------------------------------- Global Notes: Note (G1): Apparent magnitudes in the AB system. At z = 0.0, these magnitudes are absolute, i.e. based on an assumed distance of 10pc. At higher redshifts, the magnitudes are based on luminosity distances calculated using the cosmology {Omega}_M_=0.27, {Omega}_{Lambda}_=0.73 and H_0_=72km/s/Mpc. When calculating these magnitudes, the intergalactic medium (IGM) shortward of Lyman {alpha} (1216{AA} in the rest frame) has been assumed to be completely opaque at z>6. Whenever the upper or lower wavelength limit of the stellar atmosphere spectrum is redshifted into one of the JWST filters, the corresponding AB magnitude is set to 999.000. -------------------------------------------------------------------------------- ================================================================================ (End) Erik Zackrisson [Stockholm Observatory, Sweden] 25-Aug-2010