J/AJ/149/79 Spectroscopy of 299 galaxies from NewHa survey (de los Reyes+, 2015) ================================================================================ The relationship between stellar mass, gas metallicity, and star formation rate for H{alpha}-selected galaxies at z ~~ 0.8 from the NewH{alpha} survey. de los Reyes M.A., Ly C., Lee J.C., Salim S., Peeples M.S., Momcheva I., Feddersen J., Dale D.A., Ouchi M., Ono Y., Finn R. =2015AJ....149...79D ================================================================================ ADC_Keywords: Galaxies, photometry ; Galaxies, spectra ; Interstellar medium ; Photometry, infrared ; Redshifts ; Equivalent widths ; Abundances ; Balmer lines Keywords: galaxies: abundances - galaxies: evolution - galaxies: fundamental parameters - galaxies: ISM - galaxies: starburst Abstract: Using a sample of 299 H{alpha}-selected galaxies at z~~0.8, we study the relationship between galaxy stellar mass, gas-phase metallicity, and star formation rate (SFR), and compare to previous results. We use deep optical spectra obtained with the IMACS spectrograph at the Magellan telescope to measure strong oxygen lines. We combine these spectra and metallicities with (1) rest-frame UV-to-optical imaging, which allows us to determine stellar masses and dust attenuation corrections, and (2) H{alpha} narrowband imaging, which provides a robust measurement of the instantaneous SFR. Our sample spans stellar masses of ~10^9^-6x10^11^M_{sun}_, SFRs of 0.4-270M_{sun}_/yr, and metal abundances of 12+log(O/H)~~8.3-9.1(~~0.4-2.6Z_{sun}_). The correlations that we find between the H{alpha}-based SFR and stellar mass (i.e., the star-forming "main sequence") and between the stellar mass and metallicity are both consistent with previous z~1 studies of star-forming galaxies. We then study the relationship between the three properties using various plane-fitting techniques and a curve-fitting projection. In all cases, we exclude strong dependence of the M_{star}_-Z relation on SFR, but are unable to distinguish between moderate and no dependence. Our results are consistent with previous mass-metallicity-SFR studies. We check whether data set limitations may obscure a strong dependence on the SFR by using mock samples drawn from the Sloan Digital Sky Survey. These experiments reveal that the adopted signal-to-noise ratio cuts may have a significant effect on the measured dependence. Further work is needed to investigate these results, and to test whether a "fundamental metallicity relation" or a "fundamental plane" describes star-forming galaxies across cosmic time. Description: We present near-infrared narrowband photometry and optical spectroscopy for a sample of 299 H{alpha}-selected galaxies at z~0.8 from the National Optical Astronomy Observatory (NOAO) Extremely Wide-Field Infrared Imager (NEWFIRM) H{alpha} survey (NewH{alpha}; Ly et al., 2011ApJ...726..109L; Lee et al., 2012PASP..124..782L). The galaxies are identified in the Subaru/XMM Deep Survey (SXDS) field (Furusawa et al. 2008, cat. J/ApJS/176/1). The NewH{alpha} Survey is a program that has obtained emission-line selected samples at intermediate redshift. NEWFIRM at the Kitt Peak National Observatory/Cerro Tololo Inter-American Observatory (KPNO/CTIO) 4m telescopes was used to obtain observations over three fields (that roughly correspond with the Subaru/Suprime-Cam South, West, and North pointings) in the SXDS ({alpha}=2^h^18^m^; {delta}=-5{deg}) in 2007 December, 2008 September, and 2008 October. As discussed in Momcheva et al. (2013AJ....145...47M), deep follow-up spectroscopy of the NewH{alpha} narrowband 1.18{mu}m (NB118) emission-line galaxy candidate sample was performed in 2008-2009 with the Inamori Magellan Areal Camera and Spectrograph (IMACS) on the Magellan-I 6.5m Baade telescope. The chosen observational setup yields spectral coverage from 6300 to 9600{AA} (corresponding to rest frame ~3500-5300{AA}), and captures the strong rest-frame optical emission lines from [OII] {lambda}3727 (observed at ~6700{AA}) to [OIII] {lambda}5007 (observed at ~9000{AA}) for galaxies at z~0.8. Slit widths of 1.5'' were chosen (~11kpc at z=0.8). The seeing during our observing runs was generally sub-arcsecond. In Table 1, we present the NEWFIRM photometric properties of the 299 spectroscopically confirmed H{alpha} emitters in the SXDS with IMACS. We use multiband photometry (GALEX NUV, Canada-France-Hawaii Telescope (CFHT)/Megacam u-band, Subaru/Suprime-Cam BVR_C_i'z' and J) as constraints in the Spectral Energy Distribution (SED) fitting (which is discussed in Section 3.1). The NUV photometry are based on deep (46ks) GALEX imaging of the SXDS fields (PI: S. Salim, GI6-005). The optical photometry was obtained with Suprime-Cam as part of the Subaru Telescope Observatory Projects (Furusawa et al. 2008, cat. J/ApJS/176/1). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 99 299 NEWFIRM photometry of H{alpha}-selected z=0.8 galaxies table2.dat 82 299 NewH{alpha} emission-line fluxes from Magellan/IMACS table3.dat 59 299 Stellar mass, SFR, and AGN classification table4.dat 79 187 NewH{alpha} SED-corrected metallicities table5.dat 79 187 NewH{alpha} Balmer-corrected metallicities -------------------------------------------------------------------------------- See also: J/ApJ/765/140 : Stacked spectra of SDSS star forming galaxies (Andrews+, 2013) J/ApJ/735/86 : NEWFIRM MBS: photometric catalogs (Whitaker+, 2011) J/ApJ/677/169 : H{alpha} galaxies at z=0.84 (Villar+, 2008) J/ApJS/176/1 : Subaru/XMM-Newton deep survey (SXDS). II. (Furusawa+, 2008) J/ApJ/657/738 : SDF galaxies multi-photometry (Ly+, 2007) J/A+A/459/85 : O/H and gas densities in star-forming galaxies (Nagao+, 2006) J/ApJ/617/240 : Oxygen abundances in the GOODS-North field (Kobulnicky+, 2004) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 A1 --- Fld Field in the Subaru/XMM Deep Survey (SXDS) (S=South, N=North, W=West) (G1) 3- 6 A4 --- --- [SXDS] 7- 13 A7 --- SXDS Identifier in the NEWFIRM H{alpha} (NewH{alpha}) survey catalog (G2) 15 I1 h RAh Hour of Right Ascension (J2000) 17- 18 I2 min RAm Minute of Right Ascension (J2000) 20- 23 F4.1 s RAs Second of Right Ascension (J2000) 25 A1 --- DE- Sign of the Declination (J2000) 26 I1 deg DEd Degree of Declination (J2000) 28- 29 I2 arcmin DEm Arcminute of Declination (J2000) 31- 34 F4.1 arcsec DEs Arcsecond of Declination (J2000) 36- 40 F5.3 --- z [0.78/0.83] IMACS spectroscopic redshift (1) 42 A1 --- l_Jmag Limit on Jmag 44- 48 F5.2 mag Jmag [18.6/23.7]? NEWFIRM J band AB magnitude (2) 50- 53 F4.2 mag e_Jmag ? Uncertainty in Jmag 55 A1 --- l_NBmag Limit flag on NBmag 57- 61 F5.2 mag NBmag [18.23/23.41]? NEWFIRM narrowband 1.18{mu}m AB magnitude (3) 63- 66 F4.2 mag e_NBmag ? Uncertainty in NBmag 68- 72 F5.1 10-20W/m2 Flux [1/125.7]? Narrowband flux; in units of 10^-17^erg/s/cm^2^ (4) 74- 77 F4.1 10-20W/m2 e_Flux ? Uncertainty in Flux 79 A1 --- l_EW Limit flag on EW 80- 83 I4 0.1nm EW [5/270]? Narrowband rest-frame equivalent width; in {AA} 85- 87 I3 0.1nm e_EW ? Uncertainty in EW 89- 92 F4.2 --- NII/Ha ? Estimated [NII] to H{alpha} flux ratio (5) 94- 99 F6.3 [10-7W] logLHa [40.368/42.427]? Log observed H{alpha} luminosity; in erg/s (4) -------------------------------------------------------------------------------- Note (1): IMACS = Inamori Magellan Areal Camera and Spectrograph on the Magellan-I 6.5m Baade telescope. Note (2): NEWFIRM = National Optical Astronomy Observatory (NOAO) Extremely Wide-Field Infrared Imager (at the Kitt Peak National Observatory/Cerro Tololo Inter-American Observatory (KPNO/CTIO) 4m telescopes). The conversion from Vega to AB magnitudes is given by m(AB)-m(Vega)=0.87 (Ly et al., 2011ApJ...726..109L). Note (3): The conversion from Vega to AB magnitudes is given by m(AB)-m(Vega)=0.95 (Ly et al., 2011ApJ...726..109L). Note (4): For both flux and luminosity, the amount of foreground extinction is negligible, so we excluded it in our calculations. Note (5): Calculated using the narrowband equivalent width (refer to Section 3.2 for more details). Here, [NII] refers to the doublet, 6548 and 6583{AA}. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 A1 --- Fld Field in the Subaru/XMM Deep Survey (SXDS) (S=South, N=North, W=West) (G1) 3- 6 A4 --- --- [SXDS] 7- 13 A7 --- SXDS Identifier in the NEWFIRM H{alpha} (NewH{alpha}) survey catalog (G2) 15- 19 F5.2 10-20W/m2 FOII ? Magellan/IMACS spectroscopic flux for the [OII]{lambda}3726+3729{AA} emission-line (6) 21- 24 F4.2 10-20W/m2 e_FOII ? Uncertainty in FOII 26- 31 F6.2 10-20W/m2 F4959 ? Magellan/IMACS spectroscopic flux for the [OIII]{lambda}4959{AA} emission-line (6) 33- 36 F4.2 10-20W/m2 e_F4959 ? Uncertainty in F4959 38- 43 F6.2 10-20W/m2 F5007 ? Magellan/IMACS spectroscopic flux for the [OIII]{lambda}5007{AA} emission-line (6) 45- 48 F4.2 10-20W/m2 e_F5007 ? Uncertainty in F5007 50- 55 F6.2 10-20W/m2 FHb ? Magellan/IMACS spectroscopic flux for Balmer H{beta} emission-line (6) 57- 60 F4.2 10-20W/m2 e_FHb ? Uncertainty in FHb 62- 66 F5.2 10-20W/m2 FHg ? Magellan/IMACS spectroscopic flux for the Balmer H{gamma} emission-line (6) 68- 71 F4.2 10-20W/m2 e_FHg ? Uncertainty in FHg 73- 77 F5.2 10-20W/m2 FHd ? Magellan/IMACS spectroscopic flux for the Balmer H{delta} emission-line (6) 79- 82 F4.2 10-20W/m2 e_FHd ? Uncertainty in FHd -------------------------------------------------------------------------------- Note (6): IMACS = Inamori Magellan Areal Camera and Spectrograph on the Magellan-I 6.5m Baade telescope. All line fluxes are in units of 10^-17^erg/s/cm^2^. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 A1 --- Fld Field in the Subaru/XMM Deep Survey (SXDS) (S=South, N=North, W=West) (G1) 3- 6 A4 --- --- [SXDS] 7- 13 A7 --- SXDS Identifier in the NEWFIRM H{alpha} (NewH{alpha}) survey catalog (G2) 15- 19 F5.2 [Msun] logM* ? Log stellar mass determination (7) 21- 24 F4.2 [Msun] e_logM* ? Uncertainty in logM (8) 26- 30 F5.2 [Msun/yr] SFRSED ? Log star formation rate from spectral energy distribution (SED) fitting (9) 32- 35 F4.2 [Msun/yr] e_SFRSED ? Uncertainty in SFRSED 37- 41 F5.2 [Msun/yr] SFRHaS ? Log star formation rate from H{alpha} luminosity (10) 43- 46 F4.2 [Msun/yr] e_SFRHaS ? Uncertainty in SFRHaS 48- 52 F5.2 [Msun/yr] SFRHaB ? Log star formation rate from H{alpha} luminosity (11) 54- 57 F4.2 [Msun/yr] e_SFRHaB ? Uncertainty in SFRHaB 59 I1 --- AGN [1/1]?=0 Denotes an Active Galactic Nucleus (AGN) (12) -------------------------------------------------------------------------------- Note (7): As described in Section 3.1. Blanks indicate weak measurements. Note (8): The uncertainties include errors from input photometry and parameter degeneracy (e.g., with respect to star formation history and dust). Note (9): As described in Section 3.2. Blanks indicate weak measurements. Note (10): As described in Section 3.2. Dereddened using the prescription of Charlot & Fall (2000ApJ...539..718C) and spectral energy distribution (SED) results. Blanks indicate weak measurements. Note (11): As described in Section 3.2. Dereddened using the Balmer decrement. Blanks indicate weak measurements. Note (12): AGN classification was performed by Momcheva et al. (2013AJ....145...47M) using a combination of methods, including UV variability, line widths, and emission-line diagnostics with the "Mass-Excitation" diagram (Juneau et al., 2011ApJ...736..104J), to identify both broad- and narrow-line AGNs. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table[45].dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 A1 --- Fld Field in the Subaru/XMM Deep Survey (SXDS) (S=South, N=North, W=West) (G1) 3- 6 A4 --- --- [SXDS] 7- 13 A7 --- SXDS Identifier in the NEWFIRM H{alpha} (NewH{alpha}) survey catalog (G2) 15- 19 F5.3 [-] ZM91+ [7.595/9.093]? Upper metallicity Z from calibration of McGaugh (1991ApJ...380..140M) (1) 21- 25 F5.3 [-] e_ZM91+ ? Uncertainty in ZM91+ 27- 31 F5.3 [-] ZM91- [6.776/9.061]? Lower metallicity Z from calibration of McGaugh (1991ApJ...380..140M) (1) 33- 37 F5.3 [-] e_ZM91- ? Uncertainty in ZM91- 39- 43 F5.3 [-] ZZ94 [7.102/9.324]? Metallicity Z from calibration of Zaritsky et al. (1994ApJ...420...87Z) (1) 45- 49 F5.3 [-] e_ZZ94 ? Uncertainty in ZZ94 51- 55 F5.3 [-] ZT04 [7.634/9.24]? Metallicity Z from calibration of Tremonti et al. (2004ApJ...613..898T) (1) 57- 61 F5.3 [-] e_ZT04 ? Uncertainty in ZT04 63- 67 F5.3 [-] ZN06 [8.163/9.238]? Metallicity Z from calibration of Nagao et al. 2006 (cat. J/A+A/459/85) (1) 69- 73 F5.3 [-] ZKK04+ [7.361/9.155]? Upper metallicity Z from calibration of Kobulnicky & Kewley 2004 (J/ApJ/617/240) (1) 75- 79 F5.3 [-] ZKK04- [7.242/9.071]? Lower metallicity Z from calibration of Kobulnicky & Kewley 2004 (J/ApJ/617/240) (1) -------------------------------------------------------------------------------- Note (1): All metallicities are reported in form Z=12+log(O/H) and are calculated using the nebular emission lines reported in Table 2, with dust attenuation correction derived from the SED fitting (Table 4) and the Balmer decrement (H{gamma}/H{beta}) (Table 5). -------------------------------------------------------------------------------- Global Notes: Note (G1): The Subaru/XMM Deep Survey (SXDS) fields observed by the National Optical Astronomy Observatory (NOAO) Extremely Wide-Field Infrared Imager (NEWFIRM) at the Kitt Peak National Observatory (KPNO) 4m Mayall telescope roughly correspond with the Suprime-Cam South, West, and North pointings. Note (G2): Spectroscopically confirmed H{alpha} emitters in the Subaru/XMM Deep Survey (SXDS) with Inamori Magellan Areal Camera and Spectrograph (IMACS) on the Magellan-I 6.5m Baade telescope. History: From electronic version of the journal ================================================================================ (End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 09-Mar-2015