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611. AKARI observations of SMC Cepheids
ID:
ivo://CDS.VizieR/J/MNRAS/420/585
Title:
AKARI observations of SMC Cepheids
Short Name:
J/MNRAS/420/585
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work we matched the AKARI archival data to the Optical Gravitational Lensing Experiment III (OGLE-III) catalogue to derive the mid-infrared period-luminosity (PL) relations for Small Magellanic Cloud (SMC) Cepheids. Mismatched AKARI sources were eliminated using random-phase colours obtained from the full I-band light curves from OGLE-III. It was possible to derive PL relations in the N3 and N4 bands only, although the S7-, S11-, L15- and L24-band data were also tested. Random-phase correction was included when deriving the PL relation in the N3 and N4 bands using the available time of observations from AKARI data. The final adopted PL relations were N3=-3.370logP+16.527 and N4=-3.402logP+16.556. However, these PL relations may be biased due to the small number of Cepheids in the sample.
612. AKARI photometric redshift accuracy
ID:
ivo://CDS.VizieR/J/MNRAS/394/375
Title:
AKARI photometric redshift accuracy
Short Name:
J/MNRAS/394/375
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the photometric redshift accuracy achievable with the AKARI infrared data in deep multiband surveys, such as in the North Ecliptic Pole field. We demonstrate that the passage of redshifted polycyclic aromatic hydrocarbons (PAH) and silicate features into the mid-infrared wavelength window covered by AKARI is a valuable means to recover the redshifts of starburst galaxies. To this end, we have collected a sample of ~60 galaxies drawn from the Great Observatories Origins Deep Survey-North Field with spectroscopic redshift 0.5<~zspec<~1.5 and photometry from 3.6 to 24um, provided by the Spitzer, Infrared Space Observatory and AKARI satellites. The infrared spectra are fitted using synthetic galaxy spectral energy distributions which account for starburst and active nuclei emission. For ~90 per cent of the sources in our sample, the redshift is recovered with an accuracy |zphot-zspec|/(1+zspec)~<10%. A similar analysis performed on a set of simulated spectra shows that the AKARI infrared data alone can provide photometric redshifts accurate to |zphot-zspec|/(1+zspec)~10% (1sigma) at z~<2 . At higher redshifts, the PAH features are shifted outside the wavelength range covered by AKARI and the photo-z estimates rely on the less prominent 1.6um stellar bump; the accuracy achievable in this case on (1+z) is ~10-15%, provided that the active galactic nuclei contribution to the infrared emission is subdominant. Our technique is no more prone to redshift aliasing than optical-ultraviolet photo-z, and it may be possible to reduce this aliasing further with the addition of submillimetre and/or radio data.
613. AKARI-SDSS-6dFGS-2MRS galaxy sample
ID:
ivo://CDS.VizieR/J/MNRAS/474/5363
Title:
AKARI-SDSS-6dFGS-2MRS galaxy sample
Short Name:
J/MNRAS/474/5363
Date:
21 Oct 2021
Publisher:
CDS
Description:
Local infrared (IR) luminosity functions (LFs) are necessary benchmarks for high-redshift IR galaxy evolution studies. Any accurate IR LF evolution studies require accordingly accurate local IR LFs. We present IR galaxy LFs at redshifts of z<=0.3 from AKARI space telescope, which performed an all-sky survey in six IR bands (9, 18, 65, 90, 140, and 160um) with 10 times better sensitivity than its precursor Infrared Astronomical Satellite. Availability of 160um filter is critically important in accurately measuring total IR luminosity of galaxies, covering across the peak of the dust emission. By combining data from Wide-field Infrared Survey Explorer (WISE), Sloan Digital Sky Survey (SDSS) Data Release 13 (DR 13), six-degree Field Galaxy Survey and the 2MASS Redshift Survey, we created a sample of 15638 local IR galaxies with spectroscopic redshifts, factor of 7 larger compared to previously studied AKARI-SDSS sample. After carefully correcting for volume effects in both IR and optical, the obtained IR LFs agree well with previous studies, but comes with much smaller errors. Measured local IR luminosity density is {OMEGA}_IR_=1.19+/-0.05x10^8^L_{sun}_/Mpc^3^. The contributions from luminous IR galaxies and ultraluminous IR galaxies to {OMEGA}_IR_ are very small, 9.3 per cent and 0.9 per cent, respectively. There exists no future all-sky survey in far-IR wavelengths in the foreseeable future. The IR LFs obtained in this work will therefore remain an important benchmark for high-redshift studies for decades.
614. AKARI SMC photometry
ID:
ivo://CDS.VizieR/J/PASJ/62/273
Title:
AKARI SMC photometry
Short Name:
J/PASJ/62/273
Date:
21 Oct 2021
Publisher:
CDS
Description:
We carried out near- to mid-infrared imaging and spectroscopic observations of patchy areas in the Small Magellanic Cloud using the Infrared Camera aboard AKARI. Two 100arcmin^2^ areas were imaged in 3.2, 4.1, 7, 11, 15, and 24um, and also spectroscopically observed in the wavelength range continuously from 2.5 to 13.4um. The spectral resolving power, {lambda}{Delta}{lambda}, values were about 20, 50, and 50 at 3.5, 6.6, and 10.6um, respectively. Other than the two 100arcmin^2^ areas, some patchy areas were imaged and/or spectroscopically observed as well. In this paper, we overview the observations and present a list of near- to mid-infrared photometric results, which lists ~12000 near-infrared and ~1800 mid-infrared bright point sources detected in the observed areas. The 10{sigma} limits are 16.50, 16.12, 13.28, 11.26, 9.62, and 8.76 in Vega magnitudes at 3.2, 4.1, 7, 11, 15, and 24um bands, respectively.
615. AKARI 2.5-5um spectra of nearby Type-1 AGNs
ID:
ivo://CDS.VizieR/J/ApJS/216/17
Title:
AKARI 2.5-5um spectra of nearby Type-1 AGNs
Short Name:
J/ApJS/216/17
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 2.5-5.0{mu}m spectra of 83 nearby (0.002<z<0.48) and bright (K<14mag) type-1 active galactic nuclei (AGNs) taken with the Infrared Camera on board AKARI. The 2.5-5.0{mu}m spectral region contains emission lines such as Br{beta} (2.63{mu}m), Br{alpha} (4.05{mu}m), and polycyclic aromatic hydrocarbons (3.3{mu}m), which can be used for studying the black hole (BH) masses and star formation activity in the host galaxies of AGNs. The spectral region also suffers less dust extinction than in the ultra violet (UV) or optical wavelengths, which may provide an unobscured view of dusty AGNs. Our sample is selected from bright quasar surveys of Palomar-Green and SNUQSO, and AGNs with reverberation-mapped BH masses from Peterson et al. Using 11 AGNs with reliable detection of Brackett lines, we derive the Brackett-line-based BH mass estimators. We also find that the observed Brackett line ratios can be explained with the commonly adopted physical conditions of the broad line region. Moreover, we fit the hot and warm dust components of the dust torus by adding photometric data of SDSS, 2MASS, WISE, and ISO to the AKARI spectra, finding hot and warm dust temperatures of ~1100K and ~220K, respectively, rather than the commonly cited hot dust temperature of 1500K.
616. A K-selected catalog of the ECDFS from MUSYC
ID:
ivo://CDS.VizieR/J/ApJS/183/295
Title:
A K-selected catalog of the ECDFS from MUSYC
Short Name:
J/ApJS/183/295
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new, K-selected, optical-to-near infrared photometric catalog of the Extended Chandra Deep Field South (ECDFS), making it publicly available to the astronomical community. The data set is founded on publicly available imaging, supplemented by original z'JK imaging data collected as part of the MUltiwavelength Survey by Yale-Chile (MUSYC). The final photometric catalog consists of photometry derived from UU_38_BVRIz'JK imaging covering the full 1/2x1/2{deg} of the ECDFS, plus H-band photometry for approximately 80% of the field. The 5{sigma} flux limit for point sources is K^(AB)^_tot_=22.0. This is also the nominal completeness and reliability limit of the catalog: the empirical completeness for 21.75<K<22.00 is >~85%. We have verified the quality of the catalog through both internal consistency checks, and comparisons to other existing and publicly available catalogs. As well as the photometric catalog, we also present catalogs of photometric redshifts and rest-frame photometry derived from the 10-band photometry. We have collected robust spectroscopic redshift determinations from published sources for 1966 galaxies in the catalog. Based on these sources, we have achieved a (1{sigma}) photometric redshift accuracy of {Delta}z/(1+z)=0.036, with an outlier fraction of 7.8%. Most of these outliers are X-ray sources. Finally, we describe and release a utility for interpolating rest-frame photometry from observed spectral energy distributions, dubbed InterRest available via http://www.strw.leidenuniv.nl/~ent/InterRest
617. A large moving group within the LCC association
ID:
ivo://CDS.VizieR/J/ApJ/868/32
Title:
A large moving group within the LCC association
Short Name:
J/ApJ/868/32
Date:
21 Oct 2021
Publisher:
CDS
Description:
Scorpius-Centaurus is the nearest OB association, and its hundreds of members are divided into subgroups, including the Lower Centaurus Crux (LCC). Here we study the dynamics of the LCC area. We report the revelation of a large moving group containing more than 1800 intermediate- and low-mass young stellar objects and brown dwarfs that escaped identification until Gaia DR2 allowed a kinematic and photometric selection to be performed. We investigate the stellar and substellar content of this moving group using the Gaia DR2 astrometric and photometric measurements. The median distance of the members is 114.5pc, and 80% lie between 102 and 135pc from the Sun. Our new members cover a mass range of 0.02-5M_{sun}_ and add up to a total mass of about 700M_{sun}_. The present-day mass function follows a log-normal law with m_c_=0.22M_{sun}_ and {sigma}=0.64. We find more than 200 brown dwarfs in our sample. The star formation rate had its maximum of 8x10^-5^M_{sun}_/yr about 9Myr ago. We grouped the new members into four denser subgroups, which have increasing age from 7 to 10Myr, surrounded by "free-floating" young stars with mixed ages. Our isochronal ages, now based on accurate parallaxes, are compatible with several earlier studies of the region. The whole complex is presently expanding, and the expansion started between 8 and 10Myr ago. Two hundred members show infrared excess compatible with circumstellar disks from full to debris disks. This discovery provides a large sample of nearby young stellar and substellar objects for disk and exoplanet studies.
618. ALESS survey: SMGs in the ECDF-S data
ID:
ivo://CDS.VizieR/J/ApJ/806/110
Title:
ALESS survey: SMGs in the ECDF-S data
Short Name:
J/ApJ/806/110
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ALESS survey has followed up on a sample of 122 sub-millimeter sources in the Extended Chandra Deep Field South at 870{mu}m with the Atacama Large Millimeter Array (ALMA), allowing us to pinpoint the positions of sub-millimeter galaxies (SMGs) to ~0.3" and to find their precise counterparts at different wavelengths. This enabled the first compilation of the multi-wavelength spectral energy distributions (SEDs) of a statistically reliable survey of SMGs. In this paper, we present a new calibration of the magphys SED modeling code that is optimized to fit these ultraviolet-to-radio SEDs of z>1 star-forming galaxies using an energy balance technique to connect the emission from stellar populations, dust attenuation, and dust emission in a physically consistent way. We derive statistically and physically robust estimates of the photometric redshifts and physical parameters (such as stellar masses, dust attenuation, star formation rates (SFRs), and dust masses) for the ALESS SMGs.
619. ALFALFA discovery of Leo P. II. BVR photometry
ID:
ivo://CDS.VizieR/J/AJ/145/149
Title:
ALFALFA discovery of Leo P. II. BVR photometry
Short Name:
J/AJ/145/149
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from ground-based optical imaging of a low-mass dwarf galaxy discovered by the ALFALFA 21cm HI survey. Broadband (BVR) data obtained with the WIYN 3.5m telescope at Kitt Peak National Observatory (KPNO) are used to construct color-magnitude diagrams of the galaxy's stellar population down to V_o_~25. We also use narrowband H{alpha} imaging from the KPNO 2.1m telescope to identify a HII region in the galaxy. We use these data to constrain the distance to the galaxy to be between 1.5 and 2.0Mpc. This places Leo P within the Local Volume but beyond the Local Group. Its properties are extreme: it is the lowest-mass system known that contains significant amounts of gas and is currently forming stars.
620. ALFALFA discovery of Leo P. IV. VI photometry
ID:
ivo://CDS.VizieR/J/AJ/146/145
Title:
ALFALFA discovery of Leo P. IV. VI photometry
Short Name:
J/AJ/146/145
Date:
21 Oct 2021
Publisher:
CDS
Description:
Leo P is a low-luminosity dwarf galaxy discovered through the blind HI Arecibo Legacy Fast ALFA survey. The HI and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and an underlying older population, as well as an extremely low oxygen abundance. Here, we measure the distance to Leo P by applying the tip of the red giant branch (TRGB) distance method to photometry of the resolved stellar population from new Large Binocular Telescope V and I band imaging. We measure a distance modulus of 26.19^+0.17^_-0.50_mag corresponding to a distance of 1.72^+0.14^_0.40_Mpc. Although our photometry reaches 3mag below the TRGB, the sparseness of the red giant branch yields higher uncertainties on the lower limit of the distance. Leo P is outside the Local Group with a distance and velocity consistent with the local Hubble flow. While located in a very low-density environment, Leo P lies within ~0.5Mpc of a loose association of dwarf galaxies which include NGC 3109, Antlia, Sextans A, and Sextans B, and 1.1Mpc away from its next nearest neighbor, Leo A. Leo P is one of the lowest metallicity star-forming galaxies known in the nearby universe, comparable in metallicity to I Zw 18 and DDO 68, but with stellar characteristics similar to dwarf spheriodals (dSphs) in the Local Volume such as Carina, Sextans, and Leo II. Given its physical properties and isolation, Leo P may provide an evolutionary link between gas-rich dwarf irregular galaxies and dSphs that have fallen into a Local Group environment and been stripped of their gas.

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