- ID:
- ivo://CDS.VizieR/J/A+A/559/A132
- Title:
- AKARI NEP Deep Survey revised catalog
- Short Name:
- J/A+A/559/A132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the revised catalogue of the AKARI North Ecliptic Pole Deep survey. The survey was carried out with the InfraRed Camera (IRC) onboard AKARI which has a comprehensive mid-IR wavelength coverage in nine photometric bands at 2-24 micron. For mid-IR source extraction we used a detection image while for near-IR source detection we used optical to near-IR ground-based catalogue which is based on CFHT/MegaCam z', CFHT/WIRCam Ks and Subaru/Scam z' band detection. Here we present an AKARI source with the identification from the ground-based catalogue. For objects with multiple counterparts, all of these were listed in the catalogue with an upper limit for the AKARI flux. The magnitudes are given in the AB system.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/846
- Title:
- AKARI NEP Survey sources at 18um
- Short Name:
- J/MNRAS/444/846
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first galaxy counts at 18{mu}m using the Japanese AKARI satellite's survey at the North Ecliptic Pole (NEP), produced from the images from the NEP-Deep and NEP-Wide surveys covering 0.6 and 5.8deg^2^, respectively. We describe a procedure using a point source filtering algorithm to remove background structure and a minimum variance method for our source extraction and photometry that delivers the optimum signal to noise for our extracted sources, confirming this by comparison with standard photometry methods. The final source counts are complete and reliable over three orders of magnitude in flux density, resulting in sensitivities (80 per cent completeness) of 0.15 and 0.3mJy for the NEP-Deep and NEP-Wide surveys, respectively, a factor of 1.3 deeper than previous catalogues constructed from this field. The differential source counts exhibit a characteristic upturn from Euclidean expectations at around a milliJansky and a corresponding evolutionary bump between 0.2-0.4mJy consistent with previous mid-infrared surveys with ISO and Spitzer at 15 and 24{mu}m. We compare our results with galaxy evolution models confirming the striking divergence from the non-evolving scenario. The models and observations are in broad agreement implying that the source counts are consistent with a strongly evolving population of luminous infrared galaxies at redshifts higher than unity. Integrating our source counts down to the limit of the NEP survey at the 150{mu}Jy level we calculate that AKARI has resolved approximately 55 per cent of the 18{mu}m cosmic infrared background relative to the predictions of contemporary source count models.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/4937
- Title:
- AllWISE ctp to ROSAT/2RXS & XMMSLEW2 catalogs
- Short Name:
- J/MNRAS/473/4937
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We release the AllWISE counterparts and Gaia matches to 106573 and 17665 X-ray sources detected in the ROSAT 2RXS and XMMSL2 surveys with |b|>15{deg}. These are the brightest X-ray sources in the sky, but their position uncertainties and the sparse multi-wavelength coverage until now rendered the identification of their counterparts a demanding task with uncertain results. New all-sky multi-wavelength surveys of sufficient depth, like AllWISE and Gaia, and a new Bayesian statistics based algorithm, NWAY, allow us, for the first time, to provide reliable counterpart associations. NWAY extends previous distance and sky density based association methods and, using one or more priors (e.g. colours, magnitudes), weights the probability that sources from two or more catalogues are simultaneously associated on the basis of their observable characteristics. Here, counterparts have been determined using a Wide-field Infrared Survey Explorer (WISE) colour-magnitude prior. A reference sample of 4524 XMM/Chandra and Swift X-ray sources demonstrates a reliability of 94.7 per cent (2RXS) and 97.4 per cent (XMMSL2). Combining our results with Chandra-COSMOS data, we propose a new separation between stars and AGN in the X-ray/WISE flux-magnitude plane, valid over six orders of magnitude. We also release the NWAY code and its user manual. NWAY was extensively tested with XMM-COSMOS data. Using two different sets of priors, we find an agreement of 96 per cent and 99 per cent with published Likelihood Ratio methods. Our results were achieved faster and without any follow-up visual inspection. With the advent of deep and wide area surveys in X-rays (e.g. SRG/eROSITA, Athena/WFI) and radio (ASKAP/EMU, LOFAR, APERTIF, etc.) NWAY will provide a powerful and reliable counterpart identification tool. See for all the options the Nway manual at https://github.com/JohannesBuchner/nway/raw/master/doc/nway-manual.pdf
- ID:
- ivo://CDS.VizieR/II/328
- Title:
- AllWISE Data Release
- Short Name:
- II/328
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Wide-field Infrared Survey Explorer (WISE; see Wright et al. 2010AJ....140.1868W) is a NASA Medium Class Explorer mission that conducted a digital imaging survey of the entire sky in the 3.4, 4.6, 12 and 22um mid-infrared bandpasses (hereafter W1, W2, W3 and W4). The AllWISE program extends the work of the successful Wide-field Infrared Survey Explorer mission by combining data from the cryogenic and post-cryogenic survey phases to form the most comprehensive view of the mid-infrared sky currently available. AllWISE has produced a new Source Catalog and Image Atlas with enhanced sensitivity and accuracy compared with earlier WISE data releases. Advanced data processing for AllWISE exploits the two complete sky coverages to measure source motions for each Catalog source, and to compile a massive database of light curves for those objects.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A115
- Title:
- ALMA and NACO observations towards V1400 Cen
- Short Name:
- J/A+A/633/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our aim was to directly detect the thermal emission of the putative exoring system responsible for the complex deep transits observed in the light curve for the young Sco-Cen star 1SWASP J140747.93-394542.6 (V1400 Cen, hereafter J1407), confirming it as the occulter seen in May 2007, and to determine its orbital parameters with respect to the star. We used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the field centred on J1407 in the 340GHz (Band 7) continuum in order to determine the flux and astrometric location of the ring system relative to the star. We used the VLT/NACO camera to observe the J1407 system in March 2019 and to search for the central planetary mass object at thermal infrared wavelengths. We detect no point source at the expected location of J1407, and derive an upper limit 3{sigma} level of 57.6uJy. There is a point source detected at an angular separation consistent with the expected location for a free-floating ring system that occulted J1407 in May 2007, with a flux of 89uJy consistent with optically thin dust surrounding a massive substellar companion. At 3.8 microns with the NACO camera, we detect the star J1407 but no other additional point sources within 1.3 arcseconds of the star, with a lower bound on the sensitivity of 6MJup at the location of the ALMA source, and down to 4MJup in the sky background limit. The ALMA upper limit at the location of J1407 implies that a hypothesised bound ring system is composed of dust smaller than 1 mm in size, implying a young ring structure. The detected ALMA source has multiple interpretations, including: (i) it is an unbound substellar object surrounded by warm dust in Sco-Cen with an upper mass limit of 6M_Jup_, or (ii) it is a background galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/882/5
- Title:
- ALMA data for 5 luminous & ultraluminous IR gal.
- Short Name:
- J/ApJ/882/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new analysis of high-resolution data from the Atacama Large Millimeter/submillimeter Array for five luminous or ultraluminous infrared galaxies gives a slope for the Kennicutt-Schmidt (KS) relation equal to 1.74_-0.07_^+0.09^ for gas surface densities {Sigma}_mol_>10^3^M_{sun}_/pc^2^ and an assumed constant CO-to-H2 conversion factor. The velocity dispersion of the CO line, {sigma}_v_, scales approximately as the inverse square root of {Sigma}_mol_, making the empirical gas scale height determined from H~0.5{sigma}^2^/({pi}G{Sigma}_mol_) nearly constant, 150-190pc, over 1.5 orders of magnitude in {Sigma}_mol_. This constancy of H implies that the average midplane density, which is presumably dominated by CO-emitting gas for these extreme star-forming galaxies, scales linearly with the gas surface density, which in turn implies that the gas dynamical rate (the inverse of the freefall time) varies with {Sigma}_mol_^1/2^, thereby explaining most of the super-linear slope in the KS relation. Consistent with these relations, we also find that the mean efficiency of star formation per freefall time is roughly constant, 5%-7%, and the gas depletion time decreases at high {Sigma}_mol_, reaching only ~16Myr at {Sigma}_mol_~10^4^M_{sun}_/pc^2^. The variation of {sigma}_v_ with {Sigma}_mol_ and the constancy of H are in tension with some feedback-driven models, which predict {sigma}_v_ to be more constant and H to be more variable. However, these results are consistent with simulations in which large-scale gravity drives turbulence through a feedback process that maintains an approximately constant Toomre Q instability parameter.
- ID:
- ivo://CDS.VizieR/J/A+A/627/L6
- Title:
- ALMA Long Baseline maps of G17.64+0.16
- Short Name:
- J/A+A/627/L6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the highest angular resolution (20x15mas - 44x33au) Atacama Large Millimeter/sub-millimeter Array (ALMA) observations currently possible of the proto-O-star G17.64+0.16 in Band 6. The Cycle 5 observations with baselines out to 16 km probes scales <50au and reveal the rotating disc around G17.64+0.16, a massive forming O-type star. The disc has a ring-like enhancement in the dust emission, especially visible as arc structures to the north and south. The Keplerian kinematics are most prominently seen in the vibrationally excited water line, H_2_O (Eu=3461.9K). The mass of the central source found by modelling the Keplerian rotation is consistent with 45+/-10M_{sun}_. The H30alpha (231.9GHz) radio-recombination line and the SiO (5-4) molecular line were detected at up to the 10-sigma level. The estimated disc mass is 0.6-2.6M_{sun}_ under the optically thin assumption. Analysis of the Toomre Q parameter, in the optically thin regime, indicates that the disc stability is highly dependent on temperature. The disc currently appears stable for temperatures >150K, this does not preclude that the substructures formed earlier through disc fragmentation.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A31
- Title:
- ALMA maps of G17.64+0.16
- Short Name:
- J/A+A/620/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high angular resolution (~0.2") continuum and molecular emission line Atacama Large Millimeter/sub-millimeter Array (ALMA) observations of G17.64+0.16 in Band 6 (220-230GHz) taken as part of a campaign in search of circumstellar discs around (proto)-O-stars. At a resolution of ~400au the main continuum core is essentially unresolved and isolated from other strong and compact emission peaks. We detect SiO (5-4) emission that is marginally resolved and elongated in a direction perpendicular to the large-scale outflow seen in the ^13^CO (2-1) line using the main ALMA array in conjunction with the Atacama Compact Array (ACA). Morphologically, the SiO appears to represent a disc-like structure. Using parametric models we show that the position-velocity profile of the SiO is consistent with the Keplerian rotation of a disc around an object between 10-30M_{sun}_ in mass, only if there is also radial expansion from a separate structure. The radial motion component can be interpreted as a disc wind from the disc surface. Models with a central stellar object mass between 20 and 30M_{sun}_ are the most consistent with the stellar luminosity 1x10^5^L_{sun}_) and indicative of an O-type star. The H30{alpha} millimetre recombination line (231.9GHz) is also detected, but spatially unresolved, and is indicative of a very compact, hot, ionised region co-spatial with the dust continuum core. The broad line-width of the H30{alpha} emission (Full-Width-Half-Maximum=81.9km/s is not dominated by pressure-broadening but is consistent with underlying bulk motions. These velocities match those required for shocks to release silicon from dust grains into the gas phase. CH_3_CN and CH_3_OH thermal emission also shows two arc shaped plumes that curve away from the disc plane. Their coincidence with OH maser emission suggests that they could trace the inner working surfaces of a wide-angle wind driven by G17.64 which impacts the diffuse remnant natal cloud before being redirected into the large-scale outflow direction. Accounting for all observables, we suggest that G17.64 is consistent with a O-type young stellar object in the final stages of protostellar assembly, driving a wind, but that has not yet developed into a compact HII region. The existence and detection of the disc in G17.64 is likely related to its isolated and possibly more evolved nature, traits which may underpin discs in similar sources.
