MIGHTEE-HI: The HI emission project of the MeerKAT MIGHTEE survey
Natasha Maddox, Bradley S. Frank, A. A. Ponomareva, M. J. Jarvis, E. A. K. Adams, R. Davé, T. A. Oosterloo, M. G. Santos, S. L. Blyth, M. Glowacki, R. C. Kraan-… 展开作者
Natasha Maddox, Bradley S. Frank, A. A. Ponomareva, M. J. Jarvis, E. A. K. Adams, R. Davé, T. A. Oosterloo, M. G. Santos, S. L. Blyth, M. Glowacki, R. C. Kraan-Korteweg, W. Mulaudzi, B. Namumba, I. Prandoni, S. H. A. Rajohnson, K. Spekkens, N. J. Adams, R. A. A. Bowler, J. D. Collier, I. Heywood, S. Sekhar, A. R. Taylor
备注：
14 pages, 9 figures, accepted for publication in A&A
We present the HI emission project within the MIGHTEE survey, currently being carried out with the newly commissioned MeerKAT radio telescope. This is one of the first deep, blind, medium-wide interferometric surveys for neutral hydrogen (HI) ever undertaken, extending our knowledge of HI emission to z=0.6. The science goals of this medium-deep, medium-wide survey are extensive, including the evolution of the neutral gas content of galaxies over the past 5 billion years. Simulations predict nearly 3000 galaxies over 0<z<0.4 will be detected directly in HI, with statistical detections extending to z=0.6. The survey allows us to explore HI as a function of galaxy environment, with massive groups and galaxy clusters within the survey volume. Additionally, the area is large enough to contain as many as 50 local galaxies with HI mass $<10^8$ Msun, which allows us to study the low-mass galaxy population. The 20 deg$^2$ main survey area is centred on fields with exceptional multi-wavelength ancillary data, with photometry ranging from optical through far-infrared wavelengths, supplemented with multiple spectroscopic campaigns. We describe here the survey design and the key science goals. We also show first results from the Early Science observations, including kinematic modelling of individual sources, along with the redshift, HI, and stellar mass ranges of the sample to date.
In this work we present a novel compute framework for reconstructing Faraday depth signals from noisy and incomplete spectro-polarimetric radio datasets. This framework is based on a compressed-sensing approach that addresses a number of outstanding issues in Faraday depth reconstruction in a systematic and scaleable manner. We apply this framework to early-release data from the MeerKAT MIGHTEE polarisation survey.
We present the serendipitous discovery of a galaxy group in the XMM-LSS field with MIGHTEE Early Science observations. Twenty galaxies are detected in HI in this $z\sim0.044$ group, with a $3σ$ column density sensitivity of $N_\mathrm{HI} = 1.6\times10^{20}\,\mathrm{cm}^{-2}$. This group has not been previously identified, despite residing in a well-studied extragalactic legacy field. We present spatially-resolved HI total intensity and velocity maps for each of the objects, which reveal environmental influence through disturbed morphologies. The group has a dynamical mass of $\log_{10}(M_\mat…
Intensity mapping (IM) with neutral hydrogen is a promising avenue to probe the large scale structure of the Universe. In this paper, we demonstrate that using the 64-dish MeerKAT radio telescope as a connected interferometer, it is possible to make a statistical detection of HI in the post-reionization Universe. With the MIGHTEE (MeerKAT International GHz Tiered Extragalactic Exploration) survey project observing in the L-band ($856 < ν< 1712$ MHz, $z < 0.66$), we can achieve the required sensitivity to measure the HI IM power spectrum on quasi-linear scales, which will provide an important c…
We report the discovery of two new giant radio galaxies (GRGs) using the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey. Both GRGs were found within a 1 deg^2 region inside the COSMOS field. They have redshifts of z=0.1656 and z=0.3363 and physical sizes of 2.4Mpc and 2.0Mpc, respectively. Only the cores of these GRGs were clearly visible in previous high resolution VLA observations, since the diffuse emission of the lobes was resolved out. However, the excellent sensitivity and uv coverage of the new MeerKAT telescope allowed this diffuse emission to be detected. …
MIGHTEE is a galaxy evolution survey using simultaneous radio continuum, spectro-polarimetry, and spectral line observations from the South African MeerKAT telescope. When complete, the survey will image $\sim$20 deg$^{2}$ over the COSMOS, E-CDFS, ELAIS-S1, and XMM-LSS extragalactic deep fields with a central frequency of 1284 MHz. These were selected based on the extensive multiwavelength datasets from numerous existing and forthcoming observational campaigns. Here we describe and validate the data processing strategy for the total intensity continuum aspect of MIGHTEE, using a single deep po…
We study the radio spectral properties of 2,094 star-forming galaxies (SFGs) by combining our early science data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey with VLA, GMRT radio data, and rich ancillary data in the COSMOS field. These SFGs are selected at VLA 3GHz, and their flux densities from MeerKAT 1.3GHz and GMRT 325MHz imaging data are extracted using the "super-deblending" technique. The median radio spectral index is $α_{\rm 1.3GHz}^{\rm 3GHz}=-0.80\pm0.01$ without significant variation across the rest-frame frequencies ~1.3-10GHz, indicating ra…
MIGHTEE: The evolving radio luminosity functions of star-forming galaxies to $z\sim 4.5$ and the cosmic history of star formation
University of Oxford（牛津大学）；UKRI STFC Rutherford Appleton Laboratory（英国研究与创新部STFC拉瑟福德阿普尔顿实验室）；University of the Western Cape（西开普大学）；Institute for Astronomy, University of Edinburgh（爱丁堡大学天文研究所）；Carnegie Observatories（卡内基观测站）；Rhodes University（罗德兹大学）
We present the observed HI size-mass relation of $204$ galaxies from the MIGHTEE Survey Early Science data. The high sensitivity of MeerKAT allows us to detect galaxies spanning more than 4 orders of magnitude in HI mass, ranging from dwarf galaxies to massive spirals, and including all morphological types. This is the first time the relation has been explored on a blind homogeneous data set which extends over a previously unexplored redshift range of $0 < z < 0.084$, i.e. a period of around one billion years in cosmic time. The sample follows the same tight logarithmic relation derived from p…
The transformation and evolution of a galaxy is strongly influenced by interactions with its environment. Neutral hydrogen (\HI) is an excellent way to trace these interactions. Here, we present \HI\ observations of the spiral galaxy NGC~895, which was previously thought to be isolated. High-sensitivity \HI\ observations from the MeerKAT large survey project MIGHTEE reveal possible interaction features, such as extended spiral arms, and the two newly discovered \HI\ companions, that drive us to change the narrative that it is an isolated galaxy. We combine these observations with deep optical …
We present deep 1.4 GHz source counts from $\sim$5 deg$^2$ of the continuum Early Science data release of the MeerKAT International Gigahertz Tiered Extragalactic Exploration (MIGHTEE) survey down to $S_{1.4\textrm{GHz}}\sim$15 $μ$Jy. Using observations over two extragalactic fields (COSMOS and XMM-LSS), we provide a comprehensive investigation into correcting the incompleteness of the raw source counts within the survey to understand the true underlying source count population. We use a variety of simulations that account for: errors in source detection and characterisation, clustering, and v…
MIGHTEE-HI: Environmental effects of cosmic filaments on extragalactic HI detections in the COSMOS and XMM-LSS fields
University of Oxford（牛津大学）；University of Cambridge（剑桥大学）；University of the Western Cape（西开普敦大学）；University of Bristol（布里斯托大学）；Universiteit Gent（根特大学）；University of Edinburgh（爱丁堡大学）；Inter-University Institute for Data Intensive Astronomy, Department of Astronomy, University of Cape Town（开普敦大学天文学系数据密集型天文跨大学研究所）；Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University（大学物理、天文与数学学院天体物理学研究中心）
Measurements of the HI intensity mapping power spectrum at low redshifts with MIGHTEE data: comparison with detected HI galaxies
University of the Western Cape（西开普敦大学）；South African Radio Astronomy Observatory (SARAO)（南非射电天文观测台）；The University of Edinburgh（爱丁堡大学）；The University of Manchester（曼彻斯特大学）
MIGHTEE-HI: The direct detection of neutral hydrogen in galaxies at $z>0.25$
University of Oxford（牛津大学）；University of the Western Cape（西开普敦大学）；Rhodes University（罗兹大学）；South African Radio Astronomy Observatory（南非射电天文观测台）；University of Hertfordshire（赫特福德大学）；Universiteit Gent（根特大学）；University of Bristol（布里斯托大学）；Queen’s University（女王大学）
We present the first measurements of HI galaxy scaling relations from a blind survey at $z>0.15$. We perform spectral stacking of 9023 spectra of star-forming galaxies undetected in HI at $0.23<z<0.49$, extracted from MIGHTEE-HI Early Science datacubes, acquired with the MeerKAT radio telescope. We stack galaxies in bins of galaxy properties ($M_*$, SFR, and sSFR, with ${\rm sSFR}\equiv M_*/{\rm SFR}$), obtaining $\gtrsim 5σ$ detections in most cases, the strongest HI-stacking detections to date in this redshift range. With these detections, we are able to measure scaling relations in the prob…
We present a novel 2D flux density model for observed HI emission lines combined with a Bayesian stacking technique to measure the baryonic Tully-Fisher relation below the nominal detection threshold. We simulate a galaxy catalogue, which includes HI lines described either with Gaussian or busy function profiles, and HI data cubes with a range of noise and survey areas similar to the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. With prior knowledge of redshifts, stellar masses and inclinations of spiral galaxies, we find that our model can reconstruct the…
我们提出的科学案例和观测计划的MeerKAT天炉座调查，HI和无线电连续调查的天炉座星系团进行与SKA前体MeerKAT。天炉座是20 Mpc以内第二大的星团，也是南半球最大的邻近星团。它的低X射线光度使它代表了大多数星系生活的环境，以及发生重大星系演化的环境。天炉座的持续增长使其成为研究星系团组装、星系团中气体吸积和剥离的物理学以及这些过程与宇宙网中中性介质之间的联系的绝佳实验室。我们将观测到一个12度的$^2$区域，其距离星团中心的投影距离为1.5百万秒差距。我们将在1kpc分辨率下研究低至1e+19 cm $^{-2}$的几倍柱密度的已分辨星系的HI形态，测量低至M（HI）5e+5 M（太阳）的HI质量函数的斜率，并在此基础上研究高至1e+19 cm的几倍柱密度的已分辨星系的HI形态。并试图在10千秒差距的分辨率下探测到宇宙网中达到1e+18 cm $^{-2}$柱密度的HI。
SuperMIGHTEE : Spectral Ages of Remnant Radio Galaxy Candidates in the XMM-LSS Field
The Inter-University Institute for Data Intensive Astronomy (IDIA)（数据密集型天文学跨大学研究所）；University of Cape Town（开普敦大学）；Physical Research Laboratory（物理研究实验室）；National Centre for Radio Astrophysics, TIFR（TIFR国家射电天文中心）；Department of Physics and Astronomy, University of the Western Cape（西开普大学物理与天文学系）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）
MOSS III: MeerKATs view on the galaxy populations in two massive galaxy clusters
Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院物理研究所）；Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University（亚当·密茨凯维奇大学物理学院天文台研究所）；National Radio Astronomy Observatory (NRAO)（美国国家射电天文台）；Tartu Observatory, University of Tartu（塔尔图大学塔尔图天文台）；National Centre for Radio Astrophysics, Tata Institute of Fundamental Research（塔塔基础研究院国家射电天体物理学中心）
We present the results of three commissioning HI observations obtained with the MeerKAT radio telescope. These observations make up part of the preparation for the forthcoming MHONGOOSE nearby galaxy survey, which is a MeerKAT large survey project that will study the accretion of gas in galaxies and the link between gas and star formation. We used the available HI data sets, along with ancillary data at other wavelengths, to study the morphology of the MHONGOOSE sample galaxy, ESO 302-G014, which is a nearby gas-rich dwarf galaxy. We find that ESO 302-G014 has a lopsided, asymmetric outer disc…
We report the discovery of large amounts of previously undetected cold neutral atomic hydrogen (\HI) around the core triplet galaxies in the nearby NGC~7232 galaxy group with MeerKAT. With a physical resolution of $\sim$1 kpc, we detect a complex web of low surface brightness \HI\ emission down to a 4$σ$ column density level of $\sim$1 $\times$ 10$^{19}$ cm$^{-2}$ (over 44 \kms ). The newly discovered H\,{\sc i} streams extend over $\sim$20 arcmin corresponding to 140~kpc in projection. This is $\sim$3 times the \HI\ extent of the galaxy triplet (52 kpc). The \HI\ debris has an \HI\ mass of $\…
Virgo Filaments VII: MeerKAT HI-imaging of the VirgoIII filament
Rhodes University（罗兹大学）；INAF – Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；Laboratoire d’Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院天体物理实验室）；LIRA, Observatoire de Paris, Université PSL, CNRS（巴黎天文台拉格朗日天体物理实验室，巴黎文理研究大学，法国国家科学研究中心）；Siena College（锡耶纳学院）；INAF – Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；University of Kansas（堪萨斯大学）；Observatoire de Paris, LUX, Collège de France, CNRS, PSL University, Sorbonne University（巴黎天文台卢克索姆实验室，法兰西公学院，法国国家科学研究中心，巴黎文理研究大学，索邦大学）；INAF – Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天文与空间科学观测站）
The Large Survey Project (LSP) "MeerKAT Absorption Line Survey" (MALS) is a blind HI 21-cm and OH 18-cm absorption line survey in the L- and UHF-bands, with the primary goal to better determine the occurrence of atomic and molecular gas in the circum-galactic and inter-galactic medium, and its redshift evolution. Here we present the first results using the UHF-band, obtained towards the strongly lensed radio source PKS1830, detecting absorption in the lens galaxy. With merely 90min of data acquired on-source for science verification and processed using the Automated Radio Telescope Imaging Pip…
We develop a machine learning-based framework to predict the HI content of galaxies using more straightforwardly observable quantities such as optical photometry and environmental parameters. We train the algorithm on z=0-2 outputs from the Mufasa cosmological hydrodynamic simulation, which includes star formation, feedback, and a heuristic model to quench massive galaxies that yields a reasonable match to a range of survey data including HI. We employ a variety of machine learning methods (regressors), and quantify their performance using the root mean square error ({\sc rmse}) and the Pearso…
We present MeerKAT 1000 MHz and 1400 MHz observations of a bright radio galaxy in the southern hemisphere, ESO~137-006. The galaxy lies at the centre of the massive and merging Norma galaxy cluster. The MeerKAT continuum images (rms ~0.02 mJy/beam at ~10" resolution) reveal new features that have never been seen in a radio galaxy before: collimated synchrotron threads of yet unknown origin, which link the extended and bent radio lobes of ESO~137-006. The most prominent of these threads stretches in projection for about 80 kpc and is about 1 kpc in width. The radio spectrum of the threads is st…
The inner $\sim$200 pc region of the Galaxy contains a 4 million M$_{\odot}$ supermassive black hole (SMBH), significant quantities of molecular gas, and star formation and cosmic ray energy densities that are roughly two orders of magnitude higher than the corresponding levels in the Galactic disk. At a distance of only 8.2 kpc, the region presents astronomers with a unique opportunity to study a diverse range of energetic astrophysical phenomena, from stellar objects in extreme environments, to the SMBH and star-formation driven feedback processes that are known to influence the evolution of…
Superclusters are the largest objects in the Universe, and they provide a unique opportunity to study how galaxy clusters are born at the junction of the cosmic web as well as the distribution of magnetic fields and relativistic particles beyond cluster volume. The field of radio astronomy is going through an exciting and important era of the Square Kilometer Array (SKA). We now have the most sensitive functional radio telescopes, such as the MeerKAT, which offers high angular resolution and sensitivity towards diffuse and faint radio sources. To study the radio environments around supercluste…
Semi-empirical constraints on the HI mass function of star-forming galaxies and $Ω_{\rm HI}$ at $z\sim 0.37$ from interferometric surveys
Université de Genève（日内瓦大学）；University of Zurich（苏黎世大学）；Università degli Studi di Padova（帕多瓦大学）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；University of the Western Cape（西开普敦大学）
