We present a new approach to study planetary nebulae using integral field spectroscopy. VLT@VIMOS datacube of the planetary nebula Abell 14 is analysed in three different ways by extracting: (i) the integrated spectrum, (ii) 1-dimensional simulated long slit spectra for different position angles and (iii) spaxel-by-spaxel spectra. These data are used to built emission-line diagnostic diagrams and explore the ionization structure and excitation mechanisms combining data from 1- and 3- dimensional photoionization models. The integrated and 1D simulated spectra are suitable for developing diagnostic diagrams, while the spaxel spectra can lead to misinterpretation of the observations. We find that the emission-line ratios of Abell 14 are consistent with UV photo-ionized emission, however there are some pieces of evidence of an additional thermal mechanism. The chemical abundances confirm its previous classification as a Type I planetary nebula, without spatial variation. We find, though, variation in the ionization correction factors (ICFs) as a function of the slit position angle. The star at the geometric centre of Abell 14 has an A5 spectral type with an effective temperature of Teff = 7909$\pm$135 K and surface gravity log(g) = 1.4$\pm$0.1 cm s$^{-2}$. Hence, this star cannot be responsible for the ionization state of the nebula. Gaia parallaxes of this star yield distances between 3.6 and 4.5 kpc in good agreement with the distance derived from a 3-dimensional photoionization modelling of Abell 14, indicating the presence of a binary system at the centre of the planetary nebula.
We explore the connection between dust and star formation, in the context of environmental effects on galaxy evolution. In particular, we exploit the susceptibility of dust to external processes to assess the influence of dense environment on star-forming galaxies. We have selected cluster Abell 1758 from the Local Cluster Substructure Survey (LoCuSS). Its complex dynamical state is an ideal test-bench to track dust removal and destruction in galaxies due to merger and accretion shocks. We present a systematic panchromatic study (from 0.15 $\rm μ$m with GALEX to 500 $\rm μ$m with Herschel) of …
We examine deep stacked Chandra observations of the galaxy cluster Abell 1795 (over 700ks) to study in depth a large (34 kpc radius) cavity in the X-ray emission. Curiously, despite the large energy required to form this cavity (4PV=4x10^60 erg), there is no obvious counterpart to the cavity on the opposite side of the cluster, which would be expected if it has formed due to jets from the central AGN inflating bubbles. There is also no radio emission associated with the cavity, and no metal enhancement or filaments between it and the BCG, which are normally found for bubbles inflated by AGN wh…
The planetary nebula (PN) Abell 48 (PN G029.0+00.4) is around a rare Wolf-Rayet [WN5] star whose stellar history is as yet unknown. Using the integral field observations of the H$α$ $λ$6563 and [N II] $λ$6584 line emissions, we conducted a comprehensive spatio-kinematic analysis of this PN. A three-dimensional spatio-kinematic ionization model was developed with the kinematic modeling tool SHAPE to replicate the observed spatially-resolved velocity channels and position--velocity diagrams. According to our kinematic analysis of the H$α$ emission, this object possesses a deformed elliptic toroi…
We present a new analysis of very deep Chandra observations of the galaxy cluster Abell 1795. Utilizing nearly 750 ks of net ACIS imaging, we are able to resolve the thermodynamic structure of the Intracluster Medium (ICM) on length scales of ~ 1 kpc near the cool core. We find several previously unresolved structures, including a high pressure feature to the north of the BCG that appears to arise from the bulk motion of Abell 1795's cool core. To the south of the cool core, we find low temperature (~ 3 keV), diffuse ICM gas extending for distances of ~ 50 kpc spatially coincident with previou…
The morphology-density relation manifests the environmental dependence of the formation and evolution of galaxies as they continuously migrate through the cosmic web to ever denser environments. As gas-rich galaxies traverse the outskirts and inner regions of galaxy clusters they experience sudden and radical changes in their gas content and star formation activity. The goal of this work is to gain an H$\,$I perspective on gas depletion mechanisms acting on galaxies and galaxy groups that are being accreted by a moderately massive galaxy cluster. We aim to study the relative importance and eff…
We present the results of a systematic search and characterisation of jellyfish galaxy candidates in the multi-cluster system A901/2, at z ~ 0.165, as part of the OMEGA survey. By visual inspecting ACS/HST F606W images looking for morphological signatures of ram-pressure stripping events in Halpha-emitting galaxies, we identify a total of 70 candidates. Out of these, 53 are clearly star-forming galaxies and 5 are highly probable AGN hosts, the classification of the remaining galaxies is more uncertain. They have late-type and irregular morphologies and most of them are part of the blue cloud w…
We present the results of a new Chandra study of the galaxy cluster A2626. The radio emission of the cluster shows a complex system of four symmetric arcs without known correlations with the X-ray emission. The mirror symmetry of the radio arcs toward the center and the presence of two optical cores in the central galaxy suggested that they may be created by pairs of precessing radio jets powered by dual AGNs inside the cD galaxy. However, previous observations failed to observe the second jetted AGN and the spectral trend due to radiative age along the radio arcs, thus challenging this interp…
Extremely metal-poor, high-ionizing starbursts in the local Universe provide unique laboratories for exploring in detail the physics of high-redshift systems. Also, their ongoing star-formation and haphazard morphology make them outstanding proxies for primordial galaxies. Using integral field spectroscopy, we spatially resolved the ISM properties and massive stars of two first-class low metallicity galaxies with Wolf-Rayet features and nebular HeII emission: Mrk178 and IZw18. In this review, we summarize our main results for these two objects.
We present a detailed exploration of the stellar mass vs. gas-phase metallicity relation (MZR) using integral field spectroscopy data obtained from ~1000 galaxies observed by the SAMI Galaxy survey. These spatially resolved spectroscopic data allow us to determine the metallicity within the same physical scale (Reff) for different calibrators. The shape of the MZ relations is very similar between the different calibrators, while there are large offsets in the absolute values of the abundances. We confirm our previous results derived using the spatially resolved data provided by the CALIFA and …
We report the first gas-phase metallicity map of a distant galaxy measured with the James Webb Space Telescope (JWST). We use the NIRISS slitless spectroscopy acquired by the GLASS Early Release Science program to spatially resolve the rest-frame optical nebular emission lines in a gravitationally lensed galaxy at $z=3.06$ behind the Abell 2744 galaxy cluster. This galaxy (dubbed GLASS-Zgrad1) has stellar mass $\sim10^{8.6} M_\odot$, instantaneous star formation rate $\sim8.6$ $M_\odot$/yr (both corrected for lensing magnification), and global metallicity one-fourth solar. From its emission li…
Using the novel $JWST$/NIRCam observations in the Abell 2744 field, we present a first spatially resolved overview of an $HST$-dark galaxy, spectroscopically confirmed at $z=2.58$ with magnification $μ\approx1.9$. While being largely invisible at $\sim$1 $μ$m with NIRCam, except for sparse clumpy sub-structures, the object is well-detected and resolved in the long-wavelength bands with a spiral shape clearly visible in F277W. By combining ancillary ALMA and $Herschel$ data, we infer that this object is an edge-on dusty spiral with an intrinsic stellar mass log$(M_*/M_\odot)\sim11.3$ and a dust…
Early Results from GLASS-JWST. XXVI. Spatially Resolved Star Formation and Balmer Decrements at $1.1<z<2.3$ from NIRISS Slitless Spectroscopy
School of Astronomy and Space Science, University of Chinese Academy of Sciences (UCAS)（中国科学院大学天文与空间科学学院）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学天文与前沿科学研究院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Department of Physics and Astronomy, University of California Davis（加州大学戴维斯分校物理与天文学系）；Centre for Astrophysics and Supercomputing, Swinburne University of Technology（斯威本科技大学天体物理学与超级计算中心）；Department of Physics and Astronomy, University of California, Los Angeles（加州大学洛杉矶分校物理与天文学系）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）
Observations from multiple gamma-ray telescopes have uncovered a high energy gamma-ray source spatially coincident with the Galactic center. Recently, a compelling model for the broad-band gamma-ray emission has been formulated which posits that high energy protons emanating from Sgr A* could produce gamma-rays through pion decays resulting from inelastic collisions with the traversed interstellar gas in the region. Models of the gas distribution in the Galactic center region imply that the resulting gamma-ray morphology would be observed as a point source with all current telescopes, but that…
Cold gas in galaxies provides a crucial test to evaluate the realism of cosmological hydrodynamical simulations. To extract the atomic and molecular hydrogen properties of the simulated galaxy population, postprocessing methods taking the local UV field into account are required. We improve upon previous studies by calculating realistic UV fields with the dust radiative transfer code SKIRT to model the atomic-to-molecular transition in TNG50, the highest-resolution run of the IllustrisTNG suite. Comparing integrated quantities such as the HI mass function, we study to what detail the UV field …
Given the absence of directly detected dark matter (DM) as weakly interacting massive particles, there is strong interest in the possibility that DM is an ultra-light scalar field, here denoted as fuzzy DM. Ultra-diffuse galaxies, with the sizes of giant galaxies and the luminosities of dwarf galaxies, have a wide range of DM halo masses, thus providing new opportunities for exploring the connections between galaxies and their DM halos. Following up on new integral field unit spectroscopic observations and dynamics modeling of the DM-dominated ultra-diffuse galaxy Dragonfly 44 in the outskirts…
The SRG/eROSITA All-Sky Survey: A comprehensive X-ray analysis of the Hydra I galaxy cluster
Universität Bonn（波恩大学）；Università degli studi di Roma ‘Tor Vergata’（罗马托维尔加塔大学）；INFN, Sezione di Roma 2（意大利国家核物理研究所罗马第二分部）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Universität Erlangen-Nürnberg（埃尔朗根-纽伦堡大学）
A recent detection of spatially extended gamma-ray emission in the central region of the Andromeda galaxy (M31) has led to several possible explanations being put forth, including dark matter annihilation and millisecond pulsars. Another possibility is that the emission in M31 can be accounted for with a purely astrophysical cosmic-ray (CR) scenario. This scenario would lead to a rich multi-wavelength emission that can, in turn, be used to test it. Relativistic cosmic-ray electrons (CRe) in magnetic fields produce radio emission through synchrotron radiation, while X-rays and gamma rays are pr…
