Correlations between H$\alpha$ Equivalent Width and Galaxy Properties at $z=0.47$: Physical or Selection-driven?

Abstract

The H$\alpha$ equivalent width (EW) is an observational proxy for specific star formation rate (sSFR) and a tracer of episodic star-formation activity. Previous assessments show that EW strongly anti-correlates with stellar mass as $M^{-0.25}$ similar to the sSFR -- stellar mass relation. However, such a correlation may be driven/formed by selection effects. In this study, we investigate how H$\alpha$ EWs correlate with galaxy properties and how selection biases could alter such correlations using a $z=0.47$ narrowband-selected sample of 1572 H$\alpha$ emitters from the Ly$\alpha$ Galaxies in the Epoch of Reionization (LAGER) survey. The sample covers 3 deg${}^2$ of COSMOS and $1.1\times 10^5$ cMpc${}^3$. We assume an intrinsic EW distribution to form mock samples of H$\alpha$ emitters (HAEs) and propagate the selection criteria to match observations, giving us control on how selection biases can affect the underlying results. We find EW intrinsically correlates with stellar mass as $W_0\propto M^{-0.16\pm 0.03}$ and decreases by a factor of $\sim 3$ from $10^7$ to $10^{10}$ M${}_{\odot }$. We find low-mass HAEs to be $\sim 320$ times more likely to have rest-frame EW$>200$Åcompared to high-mass HAEs. Combining the intrinsic EW -- stellar mass correlation with an observed SMF correctly reproduces the observed H$\alpha$ LF, while not correcting for selection effects underestimates the number of bright HAEs. This suggests that the intrinsic EW -- stellar mass correlation is physically significant and reproduces three statistical distributions of galaxy populations (LF, SMF, EW distribution). At lower masses, we find there are more high-EW outliers compared to high masses, even after taking into account selection effects. Our results suggest that high sSFR outliers indicative of bursty SF activity are intrinsically more prevalent in low-mass HAEs and not a byproduct of selection effects.

arXiv comment21 Pages, 13 Figures, 2 Tables, accepted to MNRAS

References in corpus (147)

• Galactic Stellar and Substellar Initial Mass Function
• Star Formation in Galaxies Along the Hubble Sequence
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• The physical properties of star forming galaxies in the low redshift universe
• The James Webb Space Telescope
• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• UV Star Formation Rates in the Local Universe
• The reversal of the star formation-density relation in the distant universe
• Multiwavelength study of massive galaxies at z~2. I. Star formation and galaxy growth
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• Galaxies on FIRE (Feedback In Realistic Environments): Stellar Feedback Explains Cosmologically Inefficient Star Formation
• Rest-Frame Ultraviolet Spectra of z~3 Lyman Break Galaxies
• The COSMOS2015 Catalog: Exploring the 1<z<6 Universe with half a million galaxies
• Mass assembly in quiescent and star-forming galaxies since z=4 from UltraVISTA
• Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
• The Evolution of the Stellar Mass Functions of Star-Forming and Quiescent Galaxies to z = 4 from the COSMOS/UltraVISTA Survey
• Euclid Definition Study Report
• The Star-formation Mass Sequence out to z=2.5
• Constraining the Low-Mass Slope of the Star Formation Sequence at 0.5<z<2.5
• The Herschel view of the dominant mode of galaxy growth from z=4 to the present day
• The 3D-HST Survey: Hubble Space Telescope WFC3/G141 grism spectra, redshifts, and emission line measurements for $\sim 100,000$ galaxies
• 3D-HST: A wide-field grism spectroscopic survey with the Hubble Space Telescope
• The star formation history of mass-selected galaxies in the COSMOS field
• The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lya Emitters from z=3.1 to 5.7 in the 1 deg^2 Field: Luminosity Functions and AGN
• Comparison of H-alpha and UV Star Formation Rates in the Local Volume: Systematic Discrepancies for Dwarf Galaxies
• The Dark Energy Survey Data Release 1
• UV-continuum slopes at z~4-7 from the HUDF09+ERS+CANDELS observations: Discovery of a well-defined UV-color magnitude relationship for z>=4 star-forming galaxies
• Galaxy Stellar Mass Functions from ZFOURGE/CANDELS: An Excess of Low-Mass Galaxies Since z=2 and the Rapid Buildup of Quiescent Galaxies
• Keck Spectroscopy of 3<z<7 Faint Lyman Break Galaxies: The Importance of Nebular Emission in Understanding the Specific Star Formation Rate and Stellar Mass Density
• Keck Spectroscopy of Faint 3<z<7 Lyman Break Galaxies: - I. New constraints on cosmic reionisation from the luminosity and redshift-dependent fraction of Lyman-alpha emission
• The MOSFIRE Deep Evolution Field (MOSDEF) Survey: Rest-Frame Optical Spectroscopy for ~1500 H-Selected Galaxies at 1.37 < z < 3.8
• H-alpha Observations of a Large Sample of Galaxies at z~2: Implications for Star Formation in High Redshift Galaxies
• The Evolutionary History of Lyman Break Galaxies Between Redshift 4 and 6: Observing Successive Generations of Massive Galaxies in Formation
• A large Hα survey at z=2.23, 1.47, 0.84 & 0.40: the 11 Gyr evolution of star-forming galaxies from HiZELS
• Cosmic Star Formation History and its Dependence on Galaxy Stellar Mass
• Ly-alpha Emission-Line Galaxies at z = 3.1 in the Extended Chandra Deep Field South
• The realm of the galaxy protoclusters
• The Relation Between SFR and Stellar Mass for Galaxies at 3.5 $\le z\le$ 6.5 in CANDELS
• The Characteristic Star Formation Histories of Galaxies at Redshifts z~2-7
• Evidence for Ubiquitous, High-EW Nebular Emission in z~7 Galaxies: Towards a Clean Measurement of the Specific Star Formation Rate using a Sample of Bright, Magnified Galaxies
• The SFR-M* Relation and Empirical Star-Formation Histories from ZFOURGE at 0.5 < z < 4
• Ly Alpha Emitters at z=5.7 in the Subaru Deep Field
• The Spectral Energy Distributions Of z~8 Galaxies From The IRAC Ultra Deep Fields: Emission Lines, Stellar Masses, And Specific Star Formation Rates At 650 Myr
• Dust extinction from Balmer decrements of star-forming galaxies at 0.75<z<1.5 with HST/WFC3 spectroscopy from the WISP survey
• Predicting dust extinction from the stellar mass of a galaxy
• Evidence for a Non-Uniform Initial Mass Function in the Local Universe
• The Stellar Mass Density and Specific Star Formation Rate of the Universe at z~7
• Keck Spectroscopy of Faint 3<z<7 Lyman Break Galaxies:- II. A High Fraction of Line Emitters at Redshift Six
• Subaru Deep Survey II. Luminosity Functions and Clustering Properties of Lya Emitters at z=4.86 in the Subaru Deep Field
• (Star)bursts of FIRE: observational signatures of bursty star formation in galaxies
• Completing the Census of Ly-alpha Emitters at the Reionization Epoch
• The FMOS-COSMOS survey of star-forming galaxies at z ~ 1.6. I. Hα-based star formation rates and dust extinction
• A GALEX Ultraviolet Imaging Survey of Galaxies in the Local Volume
• The DEIMOS 10k spectroscopic survey catalog of the COSMOS field
• Star formation at z=1.47 from HiZELS: An Hα+[OII] double-blind study
• Very Strong Emission-Line Galaxies in the WISP Survey and Implications for High-Redshift Galaxies
• Modeling the Effects of Star Formation Histories on Halpha and Ultra-Violet Fluxes in Nearby Dwarf Galaxies
• Star Formation at $4<z<6$ From the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH)
• The H-alpha and Infrared Star Formation Rates for the Nearby Field Galaxy Survey
• The Star Formation Main Sequence in the Hubble Space Telescope Frontier Fields
• Lyman-Alpha-Emitting Galaxies at z = 2.1 in ECDF-S: Building Blocks of Typical Present-day Galaxies?
• Spectroscopic Observations of Lyman-Break Galaxies at Redshift ~ 4, 5 and 6 in the GOODS-South Field
• Measurement of Star-Formation Rate from H-alpha in field galaxies at z=1
• The PRIsm MUlti-object Survey (PRIMUS). II. Data Reduction and Redshift Fitting
• CARS: The CFHTLS-Archive-Research Survey II. Weighing dark matter halos of Lyman-break galaxies at z=3-5
• The dependence of Star Formation on Galaxy Stellar Mass
• The stellar mass function of star-forming galaxies and the mass-dependent SFR function since z=2.23 from HiZELS
• An excess of dusty starbursts related to the Spiderweb galaxy
• The evolving SFR-M_star relation and sSFR since z~5 from the VUDS spectroscopic survey
• Evidence for a non-universal stellar initial mass function from the integrated properties of SDSS galaxies
• z~4 Halpha Emitters in GOODS : Tracing the Dominant Mode for Growth of Galaxies
• The FMOS-COSMOS survey of star-forming galaxies at z~1.6 III. Survey design, performance, and sample characteristics
• The MOSDEF Survey: Dissecting the star-formation rate vs. stellar mass relation using H$\alpha$ and H$\beta$ emission lines at z ~ 2
• Properties of $z\sim 3-6$ Lyman Break Galaxies. II. Impact of nebular emission at high redshift
• The evolution of the specific star formation rate of massive galaxies to z ~ 1.8 in the E-CDFS
• The MOSDEF Survey: Significant Evolution in the Rest-Frame Optical Emission Line Equivalent Widths of Star-Forming Galaxies at z=1.4-3.8
• GOLDRUSH. II. Clustering of Galaxies at $z\sim 4-6$ Revealed with the Half-Million Dropouts Over the 100 deg${}^2$ Area Corresponding to 1 Gpc${}^3$
• The Complete Calibration of the Color-Redshift Relation (C3R2) Survey: Survey Overview and Data Release 1
• HerMES: dust attenuation and star formation activity in UV-selected samples from z~4 to z~1.5
• Evolution of Stellar-to-Halo Mass Ratio at z=0-7 Identified by Clustering Analysis with the Hubble Legacy Imaging and Early Subaru/Hyper Suprime-Cam Survey Data
• A Closer look at Bursty Star Formation with $L_{H\alpha }$ and $L_{UV}$ Distributions
• The Nature of Extreme Emission Line Galaxies at z=1-2: Kinematics and Metallicities from Near-Infrared Spectroscopy
• A Coherent Study of Emission Lines from Broad-Band Photometry: Specific Star-Formation Rates and [OIII]/Hβ Ratio at 3 < z < 6
• The origin of scatter in the star formation rate - stellar mass relation
• Massive starburst galaxies in a z=2.16 proto-cluster unveiled by panoramic H-alpha mapping
• Constructing Merger Trees that Mimic N-Body Simulations
• Slow Evolution of the Specific Star Formation Rate at z>2: The Impact of Dust, Emission Lines, and A Rising Star Formation History
• Halpha Equivalent Widths from the 3D-HST survey: evolution with redshift and dependence on stellar mass
• The COSMOS2015 galaxy stellar mass function: 13 billion years of stellar mass assembly in 10 snapshots
• The Evolution of Ly-alpha Emitting Galaxies Between z = 2.1 and z = 3.1
• On Near-Infrared H-Alpha Searches for High-Redshift Galaxies
• Low-Redshift Ly-alpha Selected Galaxies from GALEX Spectroscopy: A Comparison with Both UV-Continuum Selected Galaxies and High-Redshift Ly-alpha Emitters
• The Large Early Galaxy Astrophysics Census (LEGA-C) Data Release II: dynamical and stellar population properties of z ~< 1 galaxies in the COSMOS field
• On the puzzling plateau in the specific star formation rate at z=2-7
• First spectroscopic measurements of [OIII] emission from Lyman-alpha selected field galaxies at z ~ 3.1
• Deficiency of large equivalent width Lyman-alpha emission in luminous Lyman break galaxies at z~5-6?
• The Recent Burstiness of Star Formation in Galaxies at z~4.5 from H$\alpha$ Measurements
• The evolution of the equivalent width of the Ha emission line and specific star-formation rate in star-forming galaxies at 1<z<5
• Inferred Hα Flux as a Star-Formation Rate Indicator at z ~ 4-5: Implications for Dust Properties, Burstiness, and the z = 4-8 Star-Formation-Rate Functions
• Star formation in galaxies at z~4-5 from the SMUVS survey: a clear starburst/main-sequence bimodality for Halpha emitters on the SFR-M* plane
• The MUSE Hubble Ultra Deep Field Survey XI. Constraining the low-mass end of the stellar mass - star formation rate relation at $z<1$
• Clustering of Lyman Break Galaxies at z=4 and 5 in The Subaru Deep Field: Luminosity Dependence of The Correlation Function Slope
• Lyman alpha emitting galaxies at 0.2 < z < 0.35 from GALEX spectroscopy
• The Bursty Star Formation Histories of Low-mass Galaxies at $0.4<z<1$ Revealed by Star Formation Rates Measured from H$\beta$ and FUV
• The 0.1<z<1.65 evolution of the bright end of the [OII] luminosity function
• Consequences of bursty star formation on galaxy observables at high redshifts
• The MUSE Hubble Ultra Deep Field Survey X. Ly$\alpha$ Equivalent Widths at $2.9<z<6.6$
• A New Constraint on Reionization from Evolution of the Ly$\alpha$ Luminosity Function at $z\sim 6-7$ Probed by a Deep Census of $z=7.0$ Ly$\alpha$ Emitter Candidates to 0.3 $L^{\ast }$
• MAHALO Deep Cluster Survey II. Characterizing massive forming galaxies in the Spiderweb protocluster at z=2.2
• Contamination of Broad-Band Photometry by Nebular Emission in High Redshift Galaxies: Investigations with Keck's MOSFIRE Near-Infrared Spectrograph
• Dust attenuation in z $\sim$ 1 galaxies from Herschel and 3D-HST H$\alpha$ measurements
• Galaxy Zoo: the dependence of the star formation-stellar mass relation on spiral disk morphology
• The GLARE Survey II. Faint z=6 Ly-alpha Line Emitters in the HUDF
• A Comprehensive Study of Ly$\alpha$ Emission in the High-redshift Galaxy Population
• The Average Physical Properties and Star Formation Histories of the UV-Brightest Star-Forming Galaxies at z~3.7
• Hubble Space Telescope Grism Spectroscopy of Extreme Starbursts Across Cosmic Time: The Role of Dwarf Galaxies in the Star Formation History of the Universe
• Tracing the star formation history of cluster galaxies using the Halpha/UV flux ratio
• Stochasticity, a variable stellar upper-mass limit, binaries and star-formation rate indicators
• The Ly$\alpha$ Luminosity Function and Cosmic Reionization at $z\sim$ 7.0: a Tale of Two LAGER Fields
• The Nature of H$\beta +$[O{\sc iii}] and [O{\sc ii}] emitters to $z\sim 5$ with HiZELS: stellar mass functions and the evolution of EWs
• Mean Halpha+[NII]+[SII] EW Inferred for Star-Forming Galaxies at z=5.1-5.4 Using High-Quality Spitzer/IRAC Photometry
• A New Constraint on the Ly$\alpha$ Fraction of UV Very Bright Galaxies at Redshift 7
• The GEEC2 spectroscopic survey of Galaxy Groups at $0.8<z<1$
• The evolution of rest-frame UV properties, Lya EWs and the SFR-Stellar mass relation at z~2-6 for SC4K LAEs
• Galaxy And Mass Assembly (GAMA): The sSFR-M* relation part I - ${\sigma }_{\mathrm{sSFR}}$-M* as a function of sample, SFR indicator and environment
• The specific star formation rate of high redshift galaxies: the case for two modes of star formation
• UVUDF: UV Luminosity Functions at the cosmic high-noon
• The clustering and evolution of H-alpha emitters at z~1 from HiZELS
• Characterization of star-forming dwarf galaxies at 0.1 $\lesssim z\lesssim$ 0.9 in VUDS: Probing the low-mass end of the mass-metallicity relation
• Star Formation Stochasticity Measured from the Distribution of Burst Indicators
• The nature of H-alpha star-forming galaxies at z~0.4 in and around Cl 0939+4713: the environment matters
• z~1 Lya Emitters I. The Luminosity Function
• The dependence of galaxy clustering on stellar mass, star-formation rate and redshift at z = 0.8-2.2, with HiZELS
• Lyα Equivalent Width Distribution of Lyα Emitting Galaxies at Redshift z $\sim$ 4.5
• The clustering of typical Ly$\alpha$ emitters from $z\sim 2.5-6$: host halo masses depend on Ly$\alpha$ and UV luminosities
• Physical Properties of Spectroscopically-Confirmed Galaxies at $z\ge 6$. III. Stellar Populations from SED Modeling with Secure Ly$\alpha$ Emission and Redshifts
• How Lyman Alpha Emission Depends On Galaxy Stellar Mass
• An evolving and mass dependent ${\sigma }_{\text{sSFR}}$-${\mathrm{M}}_{\star }$ relation for galaxies
• Redshifts of Emission Line Objects in the Hubble Ultra Deep Field
• A Faint Flux-Limited Lyman Alpha Emitter Sample at $z\sim 0.3$
• On the dependence between UV luminosity and Lyman-alpha equivalent width in high redshift galaxies
• A large, deep 3 deg${}^2$ survey of H$\alpha$, [OIII], and [OII] emitters from LAGER: constraining luminosity functions
• ZFIRE: Using H$\alpha$ equivalent widths to investigate the in situ initial mass function at z~2
• The clustering of H$\beta$+[OIII] and [OII] emitters since $z\sim 5$: dependencies with line luminosity and stellar mass
• A Two-Dimensional Spectroscopic Study of Emission Line Galaxies in the Faint Infrared Grism Survey (FIGS) I: Detection Method and Catalog
• Design for the First Narrowband Filter for the Dark Energy Camera: Optimizing the LAGER Survey for z ~ 7 Galaxies

Cited by in corpus (8)

• Statistical Analysis of H I Profile Asymmetry and Shape for Nearby Galaxies
• CLEAR: The Evolution of Spatially Resolved Star Formation in Galaxies between $0.5\lesssim z\lesssim 1.7$ using H$\alpha$ Emission Line Maps
• J-PLUS: Uncovering a large population of extreme [OIII] emitters in the local Universe
• The miniJPAS survey: Identification and characterization of the emission line galaxies down to $z<0.35$ in the AEGIS field
• The miniJPAS survey: The galaxy populations in the most massive cluster in miniJPAS, mJPC2470-1771
• Stellar Populations of Lyman-alpha Emitting Galaxies in the HETDEX Survey I: An Analysis of LAEs in the GOODS-N Field
• Emission Line Galaxies in the SHARDS Frontier Fields I: Candidate Selection and the Discovery of Bursty Hα Emitters
• The miniJPAS survey: Dissecting galaxy properties across environments with spatially resolved photometry