************************************** *** *** ** The NEWFIRM Medium-Band Survey ** *** *** ************************************** We present a K-selected catalog of objects from the NEWFIRM Medium-Band Survey (NMBS). Full details of the image processing, matching, and photometry will be found in the catalog release paper by K.E. Whitaker et al. (2011). Photometric redshifts and rest-frame colors, calculated with the EAZY code (Brammer, van Dokkum, & Coppi 2008; www.astro.yale.edu/eazy/) are provided. We also include stellar population parameters calculated with the FAST code (Kriek et al. 2009; https://www.cfa.harvard.edu/~mkriek/FAST.html). ****************************** ** The Photometric Catalogs ** ****************************** Objects were detected in the NMBS K-band image using SExtractor. Fluxes in all bands are measured in fixed 1.5 arcsecond diameter apertures in the AEGIS-N2 and COSMOS-1 fields, from the PSF- and astrometrically-matched images, including zero point offsets. All fluxes are converted to total with an aperture correction and normalized to an AB zeropoint of 25, such that: magAB = -2.5*log10(flux)+25.0 A significant fraction of the objects detected by SExtractor are actually blended objects, although classified as a single object. K.E. Whitaker et al. (2011) describe the method used to deblend the photometry of the single "parent" object into its constituent "children". We have released both the original SExtractor catalog, as well as the deblended catalog. A standard selection of galaxies can be obtained by selecting use=1 for the original and deblended catalogs, which is equivalent to wmin>0.3 and star flag=0. Also note that an additional S/N cut is optimal, depending on your science goals. The data columns are as follows: id Running ID (Note: Same ID as the photometric redshift catalog) x, y x- and y-image coordinates ra, dec J2000 right ascension and declination Ktot, eKtot Total K-flux and error in total K-flux X, eX, wX Flux with color-aperture, 1-sigma error, and weight (exptime/max(exptime)) in band X (X=CH4,CH3,CH2,CH1,Ks,K,H2,H1,J3,J2,J1,Zp,Z,Ip,I,Rp,R,G,V,B,U,NUV,FUV as well as the 12 optical medium-band images in cosmos) ftot24um_uJy Total MIPS 24 micron flux (micro Jy); error is e24um_uJy*(ftot24um_uJy/f24um_uJy) f24um_uJy, e24um_uJy Aperture flux within 6'' and error of MIPS 24 micron (micro Jy) w24um Weight of MIPS 24 micron wmin Weight of band with minimum exposure wmin_irac Weight of IRAC band with minimum exposure z_spec Spectroscopic redshift, if available (matched within 1" radius) star_flag 1=Star, 0=not; from u-J1, J1-K colors ap_col, ap_tot, tot_cor Size in arcsec of the color aperture, total aperture, and total correction applied to the color aperture flux to convert to total flux K_ellip, K_theta_J2000 K-band ellipticity and position angle from SExtractor K_R50, K_class_star K-band half-light radius and star class from SExtractor K_flags Internal flag generated by SExtractor for the K-band UH2_flags Maximum internal flag generated by SExtractor for the U-H + Ks bands (excluding K) Near_Star Signifies object is near a bright star and may photometry may be effected X_contam The ratio of the flux in neighboring objects removed to the "cleaned flux", where X = CH1,CH2,CH3,CH4,NUV,FUV contam_flag A flag that indicates if any of the IRAC or GALEX photometry has a contamination ratio >50% in any of the bands. (1 = >50% in at least 1 band, 0 = OK) nchild Number of children in the deblended catalog (nchild=-1 for children) id_parent ID of the parent (id_parent=-1 for the original catalog) use A standard selection of galaxies can be obtained by selecting use=1, which is equivalent to wmin>0.3 and star flag=0. ** Note that an additional S/N cut is optimal, depending on your science goals ** The catalog is available in ascii format (.cat) *********************************** ** Photometric Redshift Catalogs ** *********************************** We calculated photometric redshifts using the EAZY code version 1.1.9. Below is a brief summary of the columns of the photo-z catalog. Please refer to the internal webpage for a more thorough description: http://www.astro.yale.edu/eazy/internal/index.html id Running ID (matched to photometric catalog) z_spec Spectroscopic Redshift; If no zspec = -1 z_a Photometric redshift derived without the K luminosity prior z_m1 Weighted redshift without the K luminosity prior chi_a Minimum chi^2 value without the prior z_p, chi_p, z_m2 Best-fit redshift, chi^2, and P(z)-weighted redshift with the K luminosity prior odds Parameter indicating the presence of a second chi^2 minimum (1=no second minimum) l/u 68/95/99 Lower and upper 68%/95%/99% confidence intervals nfilt Number of filters used to derive the photz solution q_z See Brammer et al. 2008 z_peak Hybrid between z_p and z_m2 to address the pathological case where you have two widely-separated peaks in p(z) that have similar integrated probabilities. ** This is the default photometric redshift ** z_mc Redshift value drawn randomly from p(z), which has the property that the distribution of these redshifts for a given sample of objects very closely follows the summed p(z) distribution of those same objects. *********************** ** Rest-Frame Colors ** *********************** We calculate U-B, U-V and V-J rest-frame colors using the EAZY code version 1.1.9. The rest-frame colors computed using templates in "tweak_AEGIS/spectra.param", very similar to the EAZY v1.1 template set. The U-band zero point offset was removed when calculating the rest-frame colors. To recalculate the rest-frame colors using the public catalogs, one can use a zeropoint file where all filters have a value of 1 and the U-band zeropoint offset 1/U_zpoffset, where U_zpoffset is listed in Table 4 of Whitaker et al. 2011 (note that you must convert the zero point offset in Table from magnitudes to flux). Each rest-frame color has a separate file with the filters and columns of the output files defined below. Rest-frame filters: # 153: REST_FRAME/maiz-apellaniz_Johnson_U.res, 3.59854e+03 # 154: REST_FRAME/maiz-apellaniz_Johnson_B.res, 4.38592e+03 # 155: REST_FRAME/maiz-apellaniz_Johnson_V.res, 5.49056e+03 # 161: 2MASS/J.res, 1.23751e+04 id Running ID (matched to photometric catalog) z z_peak DM Distance modulus nfilt_fit Number of filters fit chi2_fit Minimum chi^2 value LX EAZY-interpolated color index, such that X - Y = -2.5*log(LX/LY) LY EAZY-interpolated color index, such that X - Y = -2.5*log(LX/LY) *********************************** ** Stellar Population Parameters ** *********************************** We calculated the stellar population parameters using the FAST code version 0.8d. Below is a brief summary of the columns, specifying the default and additional optional settings. For a list of frequently asked questions, please see https://www.cfa.harvard.edu/~mkriek/FAST_FAQ.html. Default Settings: # Template error function: TEMPLATE_ERROR.fast.v0.2 # AB ZP: 25.00 # Library: Bruzual & Charlot (2003) # SFH: Exponentially declining SFH: SFR ~ exp(-t/tau) # Stellar IMF: Chabrier # metallicity: 0.020 # log(tau/yr): 7.0 - 10.0, in steps of 0.20 # log(age/yr): 7.6 - 10.1, in steps of 0.10 # A_V: 0.0 - 4.0, in steps of 0.10 # z: 0.0100 - 4.0000, in steps of 0.0100 Additional Settings Available: (settings the same as above unless otherwise noted) # Library: Maraston (2005) # SFH: Exponentially declining SFH: SFR ~ exp(-t/tau) # Stellar IMF: Kroupa # Library: Bruzual & Charlot (2003) # SFH: Delayed exponential SFH: SFR ~ t exp(-t/tau) # Stellar IMF: Chabrier # Library: Maraston (2005) # SFH: Delayed exponential SFH: SFR ~ t exp(-t/tau) # Stellar IMF: Kroupa id Running ID (matched to photometric catalog) z z_peak (or z_spec where available) ltau log[tau/yr] metal metallicity lage log[age/yr] Av dust reddening (uniform screen with wavelength dependence following the Calzetti et al. (2000) reddening law) lmass log[mass/Msol] lsfr log[sfr/(Msol/yr)] (for sfr=0., lsfr is set to -99) lssfr log[ssfr*yr] la2t log[age/tau] chi2 Minimum chi^2 value