Aims. We describe the observing strategy, data reduction tools, and early results of a supernova (SN) search project, named SUDARE, conducted with the ESO VST telescope, which is aimed at measuring the rate of the different types of SNe in the redshift range 0.2 < z < 0.8. Methods. The search was performed in two of the best studied extragalactic fields, CDFS and COSMOS, for which a wealth of ancillary data are available in the literature or in public archives. We developed a pipeline for the data reduction and rapid identification of transients. As a result of the frequent monitoring of the two selected fields, we obtained light curve and colour information for the transients sources that were used to select and classify SNe by means of an especially developed tool. To accurately characterise the surveyed stellar population, we exploit public data and our own observations to measure the galaxy photometric redshifts and rest frame colours. Results. We obtained a final sample of 117 SNe, most of which are SN Ia (57%) with the remaining ones being core collapse events, of which 44% are type II, 22% type IIn and 34% type Ib/c. To link the transients, we built a catalogue of ~1.3 × 105 galaxies in the redshift range 0 < z ≤ 1, with a limiting magnitude KAB = 23.5 mag. We measured the SN rate per unit volume for SN Ia and core collapse SNe in different bins of redshifts. The values are consistent with other measurements from the literature. Conclusions. The dispersion of the rate measurements for SNe-Ia is comparable to the scatter of the theoretical tracks for single degenerate (SD) and double degenerate (DD) binary systems models, therefore it is not possible to disentangle among the two different progenitor scenarios. However, among the three tested models (SD and the two flavours of DD that either have a steep DDC or a wide DDW delay time distribution), the SD appears to give a better fit across the whole redshift range, whereas the DDC better matches the steep rise up to redshift ~1.2. The DDW instead appears to be less favoured. Unlike recent claims, the core collapse SN rate is fully consistent with the prediction that is based on recent estimates of star formation history and standard progenitor mass range.

Data Reduction

Source

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Citations (55)

Understanding Infrared Galaxy Populations: the SWIRE Legacy Survey

arXiv (Cornell University) (2006)

M. Rowan-Robinson Carol J. Lonsdale Gene A. Smith J. Surace D. L. Shupe

We discuss spectral energy distributions, photometric redshifts, redshift distributions, luminosity functions, source-counts and the far infrared to optical luminosity ratio for sources in the SWIRE Legacy Survey. The spectral energy distributions of selected SWIRE sources are modelled in terms of a simple set of galaxy and quasar templates in the optical and near infrared, and with a set of dust emission templates (cirrus, M82 starburst, Arp 220 starburst, and AGN dust torus) in the mid infrared. The optical data, together with the IRAC 3.6 and 4.5 mu data, have been used to determine photometric redshifts. For galaxies with known spectroscopic redshifts there is a notable improvement in the photometric redshift when the IRAC data are used, with a reduction in the rms scatter from 10% in (1+z) to 5%. While further spectroscopic data are needed to confirm this result, the prospect of determining good photometric redshifts for the 2 million extragalactic objects in SWIRE is excellent. The distribution of the different infrared sed types in the L{ir}/L{opt} versus L{ir} plane, where L{ir} and L{opt} are the infrared and optical bolometric luminosities, is discussed. Source-counts at 24, 70 and 160 mu are discussed, and luminosity functions at 3.6 and 24 mu are presented.

Photometric redshift

Spectral energy distribution

10.48550/arxiv.astro-ph/0603737

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Exploring AGN Activity over Cosmic Time with the SKA

V. Smolčić P. Padovani J. Delhaize I. Prandoni N. Seymour

Vernesa Smolcic∗1, Paolo Padovani2, Jacinta Delhaize1, Isabella Prandoni3, Nicholas Seymour4, Matt Jarvis5,6, Jose Afonso7,8, Manuela Magliocchetti9 Minh Huynh10, Mattia Vaccari6, Alexander Karim11 1University of Zagreb, Physics Department, Bijenicka cesta 32, 10002 Zagreb, Croatia; 2European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching b. Munchen, Germany; 3INAF Istituto di Radioastronomia, Bologna, Italy; 4International Centre for Radio Astronomy Research, Curtin University, Perth, Australia; 5 Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH, UK; 6 Physics Department, University of the Western Cape, Bellville 7535, South Africa; 7Instituto de Astrofisica e Ciencias do Espaco, Universidade de Lisboa, OAL, Tapada da Ajuda, PT1349-018 Lisboa, Portugal; 8Departamento de Fisica,

10.22323/1.215.0069

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Citations (11)

Revealing the cold dust in low-metallicity environments

Astronomy and Astrophysics (2013)

A. Rémy-Ruyer S. C. Madden F. Galliano S. Hony M. Sauvage

We present new photometric data from our Herschel Key Programme, the Dwarf Galaxy Survey (DGS), dedicated to the observation of the gas and dust in 48 low-metallicity environments. They were observed with PACS and SPIRE onboard Herschel at 70,100,160,250,350, and 500 microns. We focus on a systematic comparison of the derived FIR properties (FIR luminosity, dust mass, dust temperature and emissivity index) with more metal-rich galaxies and investigate the detection of a potential submm excess. The data reduction method is adapted for each galaxy to derive the most reliable photometry from the final maps. PACS flux densities are compared with the MIPS 70 and 160 microns bands. We use colour-colour diagrams and modified blackbody fitting procedures to determine the dust properties of the DGS galaxies. We also include galaxies from the Herschel KINGFISH sample, containing more metal-rich environments, totalling 109 galaxies. The location of the DGS galaxies on Herschel colour-colour diagrams highlights the differences in global environments of low-metallicity galaxies. The dust in DGS galaxies is generally warmer than in KINGFISH galaxies (T_DGS~32 K, T_KINGFISH~23 K). The emissivity index, beta, is ~1.7 in the DGS, but metallicity does not make a strong effect on beta. The dust-to-stellar mass ratio is lower in low-metallicity galaxies: M_dust/M_star~0.02% for the DGS vs 0.1% for KINGFISH. Per unit dust mass, dwarf galaxies emit ~6 times more in the FIR than higher metallicity galaxies. Out of the 22 DGS galaxies detected at 500 micron, 41% present an excess in the submm not explained by our dust SED model. The excess mainly appears in lower metallicity galaxies (12+log(O/H) < 8.3), and the strongest excesses are detected in the most metal-poor galaxies. We stress the need for observations longwards of the Herschel wavelengths to detect any submm excess appearing beyond 500 micron.

Irregular galaxy

10.1051/0004-6361/201321602

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The star formation rates of QSOs

Monthly Notices of the Royal Astronomical Society (2022)

M. Symeonidis Natasha Maddox M. J. Jarvis M. J. Michałowski P. Andreani

ABSTRACT We examine the far-infrared (FIR) properties of a sample of 5391 optically selected QSOs in the 0.5 < z < 2.65 redshift range down to log [νLν, 2500(erg s−1)] > 44.7, using SPIRE data from Herschel-ATLAS. We split the sample in a grid of 74 luminosity–redshift bins and compute the average optical–IR spectral energy distribution (SED) in each bin. By normalizing an intrinsic active galactic nucleus (AGN) template to the AGN optical power (at 5100 Å), we decompose the total IR emission (LIR; 8–1000 µm) into an AGN (LIR, AGN) and star-forming component (LIR, SF). We find that the AGN contribution to LIR increases as a function of AGN power, manifesting as a reduction of the ‘FIR bump’ in the average QSO SEDs. We note that LIR, SF does not correlate with AGN power; the mean star formation rates (SFRs) of AGN host galaxies are a function of redshift only and they range from ∼6 M⊙ yr−1 at z ∼ 0 to a plateau of ≲ 200 M⊙ yr−1 at z ∼ 2.6. Our results indicate that the accuracy of FIR emission as a proxy for SFR decreases with increasing AGN luminosity. We show that, at any given redshift, observed trends between IR luminosity (whether monochromatic or total) and AGN power (in the optical or X-rays) can be explained by a simple model which is the sum of two components: (i) the IR emission from star formation, uncorrelated with AGN power and (ii) the IR emission from AGN, directly proportional to AGN power in the optical or X-rays.

QSOS

10.1093/mnras/stac1359

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MIGHTEE-H i: Deep spectral line observations of the COSMOS field

Monthly Notices of the Royal Astronomical Society (2024)

Ian Heywood Anastasia A Ponomareva Natasha Maddox M. J. Jarvis B. S. Frank

The MIGHTEE survey utilises the South African MeerKAT radio telescope to observe four extragalactic deep fields, with the aim of advancing our understanding of the formation and evolution of galaxies across cosmic time. MIGHTEE's frequency coverage encompasses the $\textrm{H}\scriptstyle\mathrm{I}$ line to a redshift of z $\simeq$ 0.58, and OH megamasers to z $\simeq$ 0.9. We present the MIGHTEE-$\textrm{H}\scriptstyle\mathrm{I}$ imaging products for the COSMOS field, using a total of 94.2 h on-target and a close-packed mosaic of 15 individual pointings. The spectral imaging covers two broad, relatively interference-free regions (960-1150 and 1290-1520~MHz) within MeerKAT's L-band, with up to 26 kHz spectral resolution (5.5 km s$^{-1}$ at $z$ = 0). The median noise in the highest spectral resolution data is 74 $\mu$Jy beam$^{-1}$, corresponding to a 5$\sigma$ $\textrm{H}\scriptstyle\mathrm{I}$ mass limit of 10$^{8.5}$ M$_{\odot}$ for a 300 km s$^{-1}$ line at $z$ = 0.07. The mosaics cover $>$4 deg$^{2}$, provided at multiple angular resolution / sensitivity pairings, with an angular resolution for $\textrm{H}\scriptstyle\mathrm{I}$ at $z$ = 0 of 12$''$. We describe the spectral line processing workflow that will be the basis for future MIGHTEE-$\textrm{H}\scriptstyle\mathrm{I}$ products, and validation of, and some early results from, the spectral imaging of the COSMOS field. We find no evidence for line emission at the position of the $z$ = 0.376 \HI~line reported from the CHILES survey at a $>$94 per cent confidence level, placing a 3$\sigma$ upper limit of 8.1 $\times$ 10$^{9}$ M$_{\odot}$ on $M_{\mathrm{HI}}$ for this galaxy. A public data release accompanies this article.

Cosmos (plant)

Line (geometry)

10.1093/mnras/stae2081

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Spectroscopic Cosmological Surveys in the Far-IR

L. Spinoglio M. Magliocchetti Silvia Tommasin A. M. Di Giorgio C. Gruppioni

We show the feasibility of spectroscopic cosmological surveys with the SAFARI instrument onboard of SPICA. The work is done through simulations that make use of both empirical methods, i.e. the use of observed luminosity functions and theoretical models for galaxy formation and evolution. The relations assumed between the line emission to trace AGN and star formation activity have been derived from the observations of local samples of galaxies. The results converge to indicate the use of blind spectroscopy with the SAFARI FTS at various resolutions to study galaxy evolution from the local to the distant (z~3) Universe.

10.1051/spica/200904002

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Spectroscopic confirmation and modelling of two lensed quadruple quasars in the Dark Energy Survey public footprint

Monthly Notices of the Royal Astronomical Society (2019)

C. Spiniello A. V. Sergeyev L. Marchetti C. Tortora N. R. Napolitano

Quadruply lensed quasars are extremely rare objects, but incredibly powerful cosmological tools. Only few dozen are known in the whole sky. Here we present the spectroscopic confirmation of two new quadruplets WG0214-2105 and WG2100-4452 discovered by Agnello & Spiniello (2018) within the Dark Energy Survey (DES) public footprints. We have conducted spectroscopic follow-up of these systems with the Southern African Large Telescope as part of a program that aims at confirming the largest possible number of optically selected strong gravitational lensing systems in the Equatorial and Southern Hemisphere. For both systems, we present the spectra for the sources and deflectors that allowed us to estimate the source redshifts and unambiguously confirm their lensing nature. For the brighter deflector (WG2100-4452), we measure the stellar velocity dispersion from the spectrum. We also obtain photometry for both lenses, directly from DES multi-band images, isolating the lens galaxies from the quasar images. One of the quadruplets, WG0214-2105, was also observed by Pan-STARRS, allowing us to estimate the apparent brightness of each quasar image at two different epochs, and thus to find evidence for flux variability. This result could suggest a microlensing event for the faintest components, although intrinsic variability cannot be excluded with only two epochs. Finally, we present simple lens models for both quadruplets, obtaining Einstein radii, SIE velocity dispersions, ellipticities, and position angles of the lens systems, as well as time delay predictions assuming a concordance cosmological model.

Gravitational microlensing

Einstein radius

Velocity dispersion

Strong gravitational lensing

10.1093/mnras/stz781

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Looking At the Distant Universe with the MeerKAT Array: the HI Mass Function in the Local Universe

arXiv (Cornell University) (2024)

Amir Kazemi-Moridani A. J. Baker Marc Verheijen Eric Gawiser S.-L. Blyth

We present measurements of the neutral atomic hydrogen (HI) mass function (HIMF) and cosmic HI density ($\Omega_{\rm HI}$) at $0 \leq z \leq 0.088$ from the Looking at the Distant Universe with MeerKAT Array (LADUMA) survey. Using LADUMA Data Release 1 (DR1), we analyze the HIMF via a new "recovery matrix" (RM) method that we benchmark against a more traditional Modified Maximum Likelihood (MML) method. Our analysis, which implements a forward modeling approach, corrects for survey incompleteness and uses extensive synthetic source injections to ensure robust estimates of the HIMF parameters and their associated uncertainties. This new method tracks the recovery of sources in mass bins different from those in which they were injected and incorporates a Poisson likelihood in the forward modeling process, allowing it to correctly handle uncertainties in bins with few or no detections. The application of our analysis to a high-purity subsample of the LADUMA DR1 spectral line catalog in turn mitigates any possible biases that could result from the inconsistent treatment of synthetic and real sources. For the surveyed redshift range, the recovered Schechter function normalization, low-mass slope, and "knee" mass are $\phi_\ast = 3.56_{-1.92}^{+0.97} \times 10^{-3}$ Mpc$^{-3}$ dex$^{-1}$, $\alpha = -1.18_{-0.19}^{+0.08}$, and $\log(M_\ast/M_\odot) = 10.01_{-0.12}^{+0.31}$, respectively, which together imply a comoving cosmic HI density of $\Omega_{\rm HI}=3.09_{-0.47}^{+0.65}\times 10^{-4}$. Our results show consistency between RM and MML methods and with previous low-redshift studies, giving confidence that the cosmic volume probed by LADUMA, even at low redshifts, is not an outlier in terms of its HI content.

10.48550/arxiv.2412.11426

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