The miniJPAS survey: Identification and characterization of the emission line galaxies down to z < 0.35 in the AEGIS field

Abstract

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is expected to map thousands of square degrees of the northern sky with 56 narrowband filters (spectral resolution of R ∼ 60) in the upcoming years. This resolution allows us to study emission line galaxies (ELGs) with a minimum equivalent width of 10 Å in the Hα emission line for a median signal-to-noise ratio (S/N) of 5. This will make J-PAS a very competitive and unbiased emission line survey compared to spectroscopic or narrowband surveys with fewer filters. The miniJPAS survey covered 1 deg2, and it used the same photometric system as J-PAS, but the observations were carried out with the pathfinder J-PAS camera. In this work, we identify and characterize the sample of ELGs from miniJPAS with a redshift lower than 0.35, which is the limit to which the Hα line can be observed with the J-PAS filter system. Using a method based on artificial neural networks, we detect the ELG population and measure the equivalent width and flux of the Hα, Hβ, [O III], and [N II] emission lines. We explore the ionization mechanism using the diagrams [OIII]/Hβ versus [NII]/Hα (BPT) and EW(Hα) versus [NII]/Hα (WHAN). We identify 1787 ELGs (83%) from the parent sample (2154 galaxies) in the AEGIS field. For the galaxies with reliable EW values that can be placed in the WHAN diagram (2000 galaxies in total), we obtained that 72.8 ± 0.4%, 17.7 ± 0.4%, and 9.4 ± 0.2% are star-forming (SF), active galactic nucleus (Seyfert), and quiescent galaxies, respectively. The distribution of EW(Hα) is well correlated with the bimodal color distribution of galaxies. Based on the rest-frame (u − r)–stellar mass diagram, 94% of the blue galaxies are SF galaxies, and 97% of the red galaxies are LINERs or passive galaxies. The nebular extinction and star formation rate (SFR) were computed from the Hα and Hβ fluxes. We find that the star formation main sequence is described as log SFR [M⊙ yr−1] = 0.90−0.02+0.02 log M⋆[M⊙]−8.85−0.20+0.19 and has an intrinsic scatter of 0.20−0.01+0.01. The cosmic evolution of the SFR density (ρSFR) is derived at three redshift bins: 0 &lt; z ≤ 0.15, 0.15 &lt; z ≤ 0.25, and 0.25 &lt; z ≤ 0.35, which agrees with previous results that were based on measurements of the Hα emission line. However, we find an offset with respect to other estimates that were based on the star formation history obtained from fitting the spectral energy distribution of the stellar continuum. We discuss the origin of this discrepancy, which is probably a combination of several factors: the escape of ionizing photons, the SFR tracers, and dust attenuation, among others.

The miniJPAS survey: AGN & host galaxy co-evolution of X-ray selected sources

“…The stellar emission is attenuated following the Calzetti et al (2000) law, and the dust emission is modeled with the template from Dale et al (2014). Since our photometric data includes narrow filters, emission lines typical of star-forming regions can be detected (Martínez-Solaeche et al 2022). Because of that, we added a model for nebular gas that uses nebular templates from Inoue (2011), choosing a width of 300 km s −1 for narrow emission lines.…”

The miniJPAS Survey: Detection of the double-core Lyα morphology for two high-redshift QSOs

“…The miniJPAS survey (Bonoli et al 2021) observed four AEGIS (All-wavelength Extended Groth Strip International Survey; Davis et al 2007) fields in 2018-2019 with the pathfinder camera and detected more than 60,000 objects in a total area of 1 deg 2 . The miniJPAS survey demonstrates the capabilities and unique potential of the upcoming J-PAS survey (Hernán-Caballero et al 2021;González Delgado et al 2021;Martínez-P. T. Rahna et al: The miniJPAS Survey: Detection of double-core Lyα morphology of two high-redshift QSOs Solaeche et al 2021;Queiroz et al 2022;Martínez-Solaeche et al 2022;Chaves-Montero et al 2022). More detail about the observation and data reduction of miniJPAS is given in Bonoli et al (2021).…”

J-NEP: 60-band photometry and photometric redshifts for the James Webb Space Telescope North Ecliptic Pole Time-Domain Field

“…Most of the observing time with Pathfinder was devoted to performing a ∼1 deg 2 survey of the Extended Groth Strip with the 56 filters of J-PAS along with u, g, r, and i, reaching depths comparable to those expected for J-PAS (Bonoli et al 2021). This survey, dubbed miniJPAS, has been used to test the performance of the telescope and the Pathfinder camera (Bonoli et al 2021;Xiao et al 2021), the algorithms for detection of emission lines (Martínez-Solaeche et al 2021;Iglesias-Páramo et al 2022), star, galaxy, and quasar classification (Baqui et al 2021;Queiroz et al 2022), and photo-z calculation (Hernán-Caballero et al 2021;Laur et al 2022), as well as to obtain the first scientific results on the properties of J-PAS galaxies (González Martínez-Solaeche et al 2022;Rodríguez-Martín et al 2022) and quasars (Chaves-Montero et al 2022).…”