The 5-decade old ISYA program is evaluated in the context of the experience gathered in the field: 41 schools organized in 27 countries with a total of more than 1400 students to date. In the new era ...of fast internet connectivity, social media, virtual networks, big data and machine learning, the value of face-to-face graduate schools for regions with limited up-to-date astrophysics research is presented, together with the plan to develop the ISYA program into the next decade.
ABSTRACT We present multiwavelength identifications for the counterparts of 1088 submillimeter sources detected at 850 m in the SCUBA-2 Cosmology Legacy Survey study of the UKIRT Infrared Deep Sky ...Survey-Ultra-Deep Survey (UDS) field. By utilizing an Atacama Large Millimeter Array (ALMA) pilot study on a subset of our bright SCUBA-2 sample as a training set, along with the deep optical-near-infrared (OIR) data available in this field, we develop a novel technique, Optical-IR Triple Color (OIRTC), using z − K, K − 3.6, 3.6 − 4.5 colors to select the candidate submillimeter galaxy (SMG) counterparts. By combining radio identification and the OIRTC technique, we find counterpart candidates for 80% of the Class = 1 ≥ 4 SCUBA-2 sample, defined as those that are covered by both radio and OIR imaging and the base sample for our scientific analyses. Based on the ALMA training set, we expect the accuracy of these identifications to be 82% 20%, with a completeness of 69% 16%, essentially as accurate as the traditional p-value technique but with higher completeness. We find that the fraction of SCUBA-2 sources having candidate counterparts is lower for fainter 850 m sources, and we argue that for follow-up observations sensitive to SMGs with S850 1 mJy across the whole ALMA beam, the fraction with multiple counterparts is likely to be >40% for SCUBA-2 sources at S850 4 mJy. We find that the photometric redshift distribution for the SMGs is well fit by a lognormal distribution, with a median redshift of z = 2.3 0.1. After accounting for the sources without any radio and/or OIRTC counterpart, we estimate the median redshift to be z = 2.6 0.1 for SMGs with S850 > 1 mJy. We also use this new large sample to study the clustering of SMGs and the far-infrared properties of the unidentified submillimeter sources by stacking their Herschel SPIRE far-infrared emission.
We present the analysis of near-infrared Hubble Space Telescope imaging of 10 Fanaroff Riley II powerful radio galaxies at low redshift (0.03 < z < 0.11) optically classified as narrow-line radio ...galaxies. The photometric properties of the host galaxy are measured using galfit, and compared with those from the literature. Our high resolution near-infrared observations provide new and direct information on the central kpc-scale dust lanes in our sample that could be connected to the pc-scale torus structure. Moreover, analyzing the infrared spectrograph Spitzer spectra of our sample, we suggest properties of the dust size of the torus.
Ground-based submillimetre and millimetre wavelength blank-field surveys have identified more than 100 sources, the majority of which are believed to be dusty optically obscured starburst galaxies. ...Colours derived from various combinations of far-infrared, submillimetre, millimetre and radio fluxes provide the only currently available means to determine the redshift distribution of this new galaxy population. In this paper we apply our Monte Carlo photometric redshift technique, introduced recently by Hughes et al. in Paper I, to the multiwavelength data available for 77 galaxies selected at 850 μm and 1.25 mm. We calculate a probability distribution for the redshift of each galaxy, which includes a detailed treatment of the observational errors and uncertainties in the evolutionary model. The cumulative redshift distribution of the submillimetre galaxy population that we present in this paper, based on 50 galaxies found in wide-area SCUBA surveys, is asymmetric, and broader than those published elsewhere, with a significant high-z tail for some of the evolutionary models considered. Approximately 40 to 90 per cent of the submillimetre population is expected to have redshifts in the interval 2 ≤z≤ 4. Whilst this result is completely consistent with earlier estimates for the submillimetre galaxy population, we also show that the colours of many (≲50 per cent) individual submillimetre sources, detected only at 850 μm with non-detections at other wavelengths, are consistent with those of starburst galaxies that lie at extreme redshifts, z > 4. Spectroscopic confirmation of the redshifts, through the detection of rest-frame far-infrared–millimetre wavelength molecular transition lines, will ultimately calibrate the accuracy of this technique. We use the redshift probability distribution of HDF850.1 to illustrate the ability of the method to guide the choice of possible frequency tunings on the broad-band spectroscopic receivers that equip the large-aperture single-dish millimetre and centimetre wavelength telescopes.
Abstract
We present a multiwavelength analysis of five submillimeter sources (S
1.1mm = 0.54–2.02 mJy) that were detected during our 1.1 mm deep continuum survey in the Subaru/XMM-Newton Deep Survey ...Field (SXDF)-UDS-CANDELS field (2 arcmin2, 1σ = 0.055 mJy beam−1) using the Atacama Large Millimeter/submillimeter Array (ALMA). The two brightest sources correspond to a known single-dish (AzTEC) selected bright submillimeter galaxy (SMG), whereas the remaining three are faint SMGs newly uncovered by ALMA. If we exclude the two brightest sources, the contribution of the ALMA-detected faint SMGs to the infrared extragalactic background light is estimated to be
$\sim 4.1^{+5.4}_{-3.0}\:$
Jy deg−2, which corresponds to
$\sim 16^{+22}_{-12}\%$
of the infrared extragalactic background light. This suggests that their contribution to the infrared extragalactic background light is as large as that of bright SMGs. We identified multiwavelength counterparts of the five ALMA sources. One of the sources (SXDF-ALMA3) is extremely faint in the optical to near-infrared region despite its infrared luminosity (
$L_\mathrm{IR}\simeq 1\times 10^{12}\,L_{\odot}$
or SFR ≃ 100 M
⊙ yr−1). By fitting the spectral energy distributions at the optical-to-near-infrared wavelengths of the remaining four ALMA sources, we obtained the photometric redshifts (z
photo) and stellar masses (M
*): z
photo ≃ 1.3–2.5, M
* ≃ (3.5–9.5) × 1010 M
⊙. We also derived their star formation rates (SFRs) and specific SFRs as ≃30–200 M
⊙ yr−1 and ≃0.8–2 Gyr−1, respectively. These values imply that they are main sequence star-forming galaxies.
We report the source size distribution, as measured by ALMA millimetric continuum imaging, of a sample of 13 AzTEC-selected submillimeter galaxies (SMGs) at Z{sub phot} ~ 3.6.
We present wide-field 1.1 mm continuum imaging of the nearby spiral galaxy M 33, conducted with the AzTEC bolometer camera on ASTE. We show that the 1.1 mm flux traces the distribution of dust with
...$T$
$\sim$
20 K. Combined with far-infrared imaging at 160
$\ \mu$
m, we derived the dust temperature distribution out to a galactic radius of
$\sim$
7 kpc with a spatial resolution of
$\sim$
150 pc. Although the 1.1 mm flux was observed predominantly near star-forming regions, we found a smooth radial temperature gradient declining from
$\sim$
20 K to
$\sim$
13 K consistent with recent results from the Herschel satellite. Further comparisons of individual regions show a strong correlation between the cold dust temperature and the
$K_{\rm S}$
band brightness, but not with the ionizing flux. The observed results imply that the dominant heating source of cold dust at few hundred parsec scales is due to non-OB stars, even when associated with star-forming regions.
We present a comparison between the published optical, infrared (IR) and CO spectroscopic redshifts of 15 (sub)mm galaxies and their photometric redshifts as derived from long-wavelength ...(radio–mm–far-IR) photometric data. The redshift accuracy measured for 12 submillimetre (submm) galaxies with at least one robustly determined colour in the radio–mm–far-IR regime is δz≈ 0.30 (rms). Despite the wide range of spectral energy distributions in the local galaxies that are used in an unbiased manner as templates, this analysis demonstrates that photometric redshifts can be efficiently derived for submm galaxies with a precision of δz < 0.5 using only the rest-frame far-IR to radio wavelength data.
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