@article{shivaei_mosdef_2017,
	title = {The {MOSDEF} {Survey}: {Direct} {Observational} {Constraints} on the {Ionizing} {Photon} {Production} {Efficiency}, \${\textbackslash}xi\_\{{\textbackslash}rm ion\}\$, at z{\textasciitilde}2},
	volume = {1711},
	shorttitle = {The {MOSDEF} {Survey}},
	url = {http://adsabs.harvard.edu/abs/2017arXiv171100013S},
	abstract = {We combine spectroscopic measurements of H\${\textbackslash}alpha\$ and H\${\textbackslash}beta\$ and UV 
continuum photometry for a sample of 676 galaxies from the MOSFIRE Deep
Evolution Field survey to constrain hydrogen ionizing photon production
efficiencies (\${\textbackslash}xi\_\{{\textbackslash}rm ion\}\$, xi\_ion) at z=1.4-2.6. We find average
log(xi\_ion/[Hz erg\${\textasciicircum}\{-1\}\$])=25.06 (25.34), assuming the Calzetti (SMC)
curve when correcting the UV emission for dust attenuation. We conclude
that the large scatter of 0.28 dex in xi\_ion cannot be solely explained
by measurement uncertainties or variations in the assumed dust
attenuation curve from object to object. Rather, our analysis suggests
that the scatter in xi\_ion is also affected by galaxy-to-galaxy
variations in stellar population properties, including the slope and
upper mass cutoff of the IMF, stellar metallicity, bursty star
formation, and binary/single star evolution. Moreover, we find that
xi\_ion is elevated in galaxies with high ionization states (i.e., high
[OIII]/[OII]) and low oxygen abundances (low [NII]/H\${\textbackslash}alpha\$ and high
[OIII]/H\${\textbackslash}beta\$). However, xi\_ion does not correlate with the offset
from the z{\textasciitilde}0 star-forming locus in the BPT diagram, suggesting no change
in the hardness of ionizing radiation accompanying the offset from the
z{\textasciitilde}0 sequence. We also find that the xi\_ion of galaxies with blue UV
spectral slopes (\${\textbackslash}beta\${\textasciitilde}-2.1) is elevated by a factor of {\textasciitilde}2 relative to
the average xi\_ion of the sample. If these blue galaxies are similar to
those at z{\textgreater}6, our results suggest that a lower LyC escape fraction is
required for galaxies to maintain reionization, compared to that
previously assumed based on the canonical xi\_ion predictions from
stellar population models. We also demonstrate that even with robust,
dust-corrected H\${\textbackslash}alpha\$ measurements, the UV dust attenuation curve is
an important source of uncertainty that on average causes {\textasciitilde}0.3 dex
systematic uncertainty in xi\_ion measurements.},
	journal = {ArXiv e-prints},
	author = {Shivaei, Irene and Reddy, Naveen A. and Siana, Brian and Shapley, Alice E. and Kriek, Mariska and Mobasher, Bahram and Freeman, William R. and Sanders, Ryan L. and Coil, Alison L. and Price, Sedona H. and Fetherolf, Tara and Azadi, Mojegan and Leung, Gene and Zick, Tom},
	month = oct,
	year = {2017},
	keywords = {Astrophysics - Astrophysics of Galaxies},
	pages = {arXiv:1711.00013},
}

{"_id":"cJmoLiuuCeepp47cg","bibbaseid":"shivaei-reddy-siana-shapley-kriek-mobasher-freeman-sanders-etal-themosdefsurveydirectobservationalconstraintsontheionizingphotonproductionefficiencytextbackslashxitextbackslashrmionatztextasciitilde2-2017","author_short":["Shivaei, I.","Reddy, N. A.","Siana, B.","Shapley, A. E.","Kriek, M.","Mobasher, B.","Freeman, W. R.","Sanders, R. L.","Coil, A. L.","Price, S. H.","Fetherolf, T.","Azadi, M.","Leung, G.","Zick, T."],"bibdata":{"bibtype":"article","type":"article","title":"The MOSDEF Survey: Direct Observational Constraints on the Ionizing Photon Production Efficiency, \\${\\textbackslash}xi_\\{{\\textbackslash}rm ion\\}\\$, at z\\textasciitilde2","volume":"1711","shorttitle":"The MOSDEF Survey","url":"http://adsabs.harvard.edu/abs/2017arXiv171100013S","abstract":"We combine spectroscopic measurements of H\\${\\textbackslash}alpha\\$ and H\\${\\textbackslash}beta\\$ and UV continuum photometry for a sample of 676 galaxies from the MOSFIRE Deep Evolution Field survey to constrain hydrogen ionizing photon production efficiencies (\\${\\textbackslash}xi_\\{{\\textbackslash}rm ion\\}\\$, xi_ion) at z=1.4-2.6. We find average log(xi_ion/[Hz erg\\${\\textasciicircum}\\{-1\\}\\$])=25.06 (25.34), assuming the Calzetti (SMC) curve when correcting the UV emission for dust attenuation. We conclude that the large scatter of 0.28 dex in xi_ion cannot be solely explained by measurement uncertainties or variations in the assumed dust attenuation curve from object to object. Rather, our analysis suggests that the scatter in xi_ion is also affected by galaxy-to-galaxy variations in stellar population properties, including the slope and upper mass cutoff of the IMF, stellar metallicity, bursty star formation, and binary/single star evolution. Moreover, we find that xi_ion is elevated in galaxies with high ionization states (i.e., high [OIII]/[OII]) and low oxygen abundances (low [NII]/H\\${\\textbackslash}alpha\\$ and high [OIII]/H\\${\\textbackslash}beta\\$). However, xi_ion does not correlate with the offset from the z\\textasciitilde0 star-forming locus in the BPT diagram, suggesting no change in the hardness of ionizing radiation accompanying the offset from the z\\textasciitilde0 sequence. We also find that the xi_ion of galaxies with blue UV spectral slopes (\\${\\textbackslash}beta\\$\\textasciitilde-2.1) is elevated by a factor of \\textasciitilde2 relative to the average xi_ion of the sample. If these blue galaxies are similar to those at z\\textgreater6, our results suggest that a lower LyC escape fraction is required for galaxies to maintain reionization, compared to that previously assumed based on the canonical xi_ion predictions from stellar population models. We also demonstrate that even with robust, dust-corrected H\\${\\textbackslash}alpha\\$ measurements, the UV dust attenuation curve is an important source of uncertainty that on average causes \\textasciitilde0.3 dex systematic uncertainty in xi_ion measurements.","journal":"ArXiv e-prints","author":[{"propositions":[],"lastnames":["Shivaei"],"firstnames":["Irene"],"suffixes":[]},{"propositions":[],"lastnames":["Reddy"],"firstnames":["Naveen","A."],"suffixes":[]},{"propositions":[],"lastnames":["Siana"],"firstnames":["Brian"],"suffixes":[]},{"propositions":[],"lastnames":["Shapley"],"firstnames":["Alice","E."],"suffixes":[]},{"propositions":[],"lastnames":["Kriek"],"firstnames":["Mariska"],"suffixes":[]},{"propositions":[],"lastnames":["Mobasher"],"firstnames":["Bahram"],"suffixes":[]},{"propositions":[],"lastnames":["Freeman"],"firstnames":["William","R."],"suffixes":[]},{"propositions":[],"lastnames":["Sanders"],"firstnames":["Ryan","L."],"suffixes":[]},{"propositions":[],"lastnames":["Coil"],"firstnames":["Alison","L."],"suffixes":[]},{"propositions":[],"lastnames":["Price"],"firstnames":["Sedona","H."],"suffixes":[]},{"propositions":[],"lastnames":["Fetherolf"],"firstnames":["Tara"],"suffixes":[]},{"propositions":[],"lastnames":["Azadi"],"firstnames":["Mojegan"],"suffixes":[]},{"propositions":[],"lastnames":["Leung"],"firstnames":["Gene"],"suffixes":[]},{"propositions":[],"lastnames":["Zick"],"firstnames":["Tom"],"suffixes":[]}],"month":"October","year":"2017","keywords":"Astrophysics - Astrophysics of Galaxies","pages":"arXiv:1711.00013","bibtex":"@article{shivaei_mosdef_2017,\n\ttitle = {The {MOSDEF} {Survey}: {Direct} {Observational} {Constraints} on the {Ionizing} {Photon} {Production} {Efficiency}, \\${\\textbackslash}xi\\_\\{{\\textbackslash}rm ion\\}\\$, at z{\\textasciitilde}2},\n\tvolume = {1711},\n\tshorttitle = {The {MOSDEF} {Survey}},\n\turl = {http://adsabs.harvard.edu/abs/2017arXiv171100013S},\n\tabstract = {We combine spectroscopic measurements of H\\${\\textbackslash}alpha\\$ and H\\${\\textbackslash}beta\\$ and UV \ncontinuum photometry for a sample of 676 galaxies from the MOSFIRE Deep\nEvolution Field survey to constrain hydrogen ionizing photon production\nefficiencies (\\${\\textbackslash}xi\\_\\{{\\textbackslash}rm ion\\}\\$, xi\\_ion) at z=1.4-2.6. We find average\nlog(xi\\_ion/[Hz erg\\${\\textasciicircum}\\{-1\\}\\$])=25.06 (25.34), assuming the Calzetti (SMC)\ncurve when correcting the UV emission for dust attenuation. We conclude\nthat the large scatter of 0.28 dex in xi\\_ion cannot be solely explained\nby measurement uncertainties or variations in the assumed dust\nattenuation curve from object to object. Rather, our analysis suggests\nthat the scatter in xi\\_ion is also affected by galaxy-to-galaxy\nvariations in stellar population properties, including the slope and\nupper mass cutoff of the IMF, stellar metallicity, bursty star\nformation, and binary/single star evolution. Moreover, we find that\nxi\\_ion is elevated in galaxies with high ionization states (i.e., high\n[OIII]/[OII]) and low oxygen abundances (low [NII]/H\\${\\textbackslash}alpha\\$ and high\n[OIII]/H\\${\\textbackslash}beta\\$). However, xi\\_ion does not correlate with the offset\nfrom the z{\\textasciitilde}0 star-forming locus in the BPT diagram, suggesting no change\nin the hardness of ionizing radiation accompanying the offset from the\nz{\\textasciitilde}0 sequence. We also find that the xi\\_ion of galaxies with blue UV\nspectral slopes (\\${\\textbackslash}beta\\${\\textasciitilde}-2.1) is elevated by a factor of {\\textasciitilde}2 relative to\nthe average xi\\_ion of the sample. If these blue galaxies are similar to\nthose at z{\\textgreater}6, our results suggest that a lower LyC escape fraction is\nrequired for galaxies to maintain reionization, compared to that\npreviously assumed based on the canonical xi\\_ion predictions from\nstellar population models. We also demonstrate that even with robust,\ndust-corrected H\\${\\textbackslash}alpha\\$ measurements, the UV dust attenuation curve is\nan important source of uncertainty that on average causes {\\textasciitilde}0.3 dex\nsystematic uncertainty in xi\\_ion measurements.},\n\tjournal = {ArXiv e-prints},\n\tauthor = {Shivaei, Irene and Reddy, Naveen A. and Siana, Brian and Shapley, Alice E. and Kriek, Mariska and Mobasher, Bahram and Freeman, William R. and Sanders, Ryan L. and Coil, Alison L. and Price, Sedona H. and Fetherolf, Tara and Azadi, Mojegan and Leung, Gene and Zick, Tom},\n\tmonth = oct,\n\tyear = {2017},\n\tkeywords = {Astrophysics - Astrophysics of Galaxies},\n\tpages = {arXiv:1711.00013},\n}\n\n","author_short":["Shivaei, I.","Reddy, N. A.","Siana, B.","Shapley, A. E.","Kriek, M.","Mobasher, B.","Freeman, W. R.","Sanders, R. L.","Coil, A. L.","Price, S. H.","Fetherolf, T.","Azadi, M.","Leung, G.","Zick, T."],"key":"shivaei_mosdef_2017","id":"shivaei_mosdef_2017","bibbaseid":"shivaei-reddy-siana-shapley-kriek-mobasher-freeman-sanders-etal-themosdefsurveydirectobservationalconstraintsontheionizingphotonproductionefficiencytextbackslashxitextbackslashrmionatztextasciitilde2-2017","role":"author","urls":{"Paper":"http://adsabs.harvard.edu/abs/2017arXiv171100013S"},"keyword":["Astrophysics - Astrophysics of Galaxies"],"metadata":{"authorlinks":{}}},"bibtype":"article","biburl":"https://bibbase.org/zotero/polyphant","dataSources":["7gvjSdWrEu7z5vjjj"],"keywords":["astrophysics - astrophysics of galaxies"],"search_terms":["mosdef","survey","direct","observational","constraints","ionizing","photon","production","efficiency","textbackslash","textbackslash","ion","textasciitilde2","shivaei","reddy","siana","shapley","kriek","mobasher","freeman","sanders","coil","price","fetherolf","azadi","leung","zick"],"title":"The MOSDEF Survey: Direct Observational Constraints on the Ionizing Photon Production Efficiency, \\${\\textbackslash}xi_\\{{\\textbackslash}rm ion\\}\\$, at z\\textasciitilde2","year":2017}