AMIGA project: Active galaxies in a complete sample of isolated galaxies
J. Sabater, S. Leon, L. Verdes-Montenegro, U. Lisenfeld, J. Sulentic, S. Verley
备注：
4 pages, 1 figure, proceedings of the contributed talk given at the conference "Galaxies in Isolation: Exploring Nature vs. Nurture" held in Granada, May 12-15, 2009
The project AMIGA (Analysis of the interstellar Medium of Isolated GAlaxies) provides a statistically significant sample of the most isolated galaxies in the northern sky. Such a control sample is necessary to understand the role of the environment in evolution and galaxy properties like the interstellar medium (ISM), star formation and nuclear activity. The data is publicly released under a VO interface at http://amiga.iaa.es/. One of our main goals is the study of nuclear activity in non-interacting galaxies using different methods. We focus on the well known radiocontinuum-far infrared (FIR) correlation in order to findradio-excess galaxies which are candidates to host an active galactic nucleus (AGN) and FIR colours to find obscured AGN candidates. We looked for the existing information on nuclear activity in the Véron-Cetty catalogue and in the NASA Extragalactic Database (NED). We also used the nuclear spectra from the Sloan Digital Sky Survey which allow us to determine the possible presence of an AGN and to study the properties of the underlying stellar populations. We produced a final catalogue of AGN-candidate galaxies which will provide a baseline for the study of the nuclear activity depending on the environment. We find that the fraction of FIR selected AGN-candidates ranges between 7% and 20%. There are no radio-excess galaxies in our sample above a factor 5 of radio excess which is the lowest rate found in comparison with other samples in denser environments. Finally, we obtained a fraction of about 22% of AGN using the optical spectra, a significant fraction for a sample of isolated galaxies. We conclude that the environment plays a crucial and direct role in triggering radio nuclear activity and not only via the density-morphology or the density-luminosity relations.
The role of the environment on galaxy evolution is still not fully understood. In order to quantify and set limits on the role of nurture one must identify and study a sample of isolated galaxies. The AMIGA project "Analysis of the Interstellar Medium of Isolated GAlaxies" is doing a multi-wavelength study of a large sample of isolated galaxies in order to examine their interstellar medium and star formation activity. We processed data for 950 galaxies from the Catalogue of Isolated Galaxies (CIG, Karachentseva 1973) and evaluated their isolation using an automated star-galaxy classification p…
Using mid-infrared star formation rate and stellar mass indicators in $\textit{WISE}$, we construct and contrast the relation between star formation rate and stellar mass for isolated and paired galaxies. Our samples comprise a selection of AMIGA (isolated galaxies) and pairs of ALFALFA galaxies with HI detections such that we can examine the relationship between HI content (gas fraction, HI deficiency) and galaxy location on the main sequence (MS) in these two contrasting environments. We derive for the first time an HI scaling relation for isolated galaxies using $\textit{WISE}$ stellar mass…
We present the largest catalogue of HI single dish observations of isolated galaxies to date and the corresponding HI scaling relations, as part of the multi-wavelength project AMIGA (Analysis of the interstellar Medium in Isolated GAlaxies). Despite numerous studies of the HI content of galaxies, no revision has been made for the most isolated L* galaxies since 1984. In total we have measurements or constraints on the HI masses of 844 galaxies from the Catalogue of Isolated Galaxies (CIG), obtained with our own observations at Arecibo, Effelsberg, Nancay and GBT, and spectra from the literatu…
Using images from Sloan Digital Sky Survey Data Release 8, we have re-examined the morphology of 719 galaxies from the Analysis of the interstellar Medium in Isolated GAlaxies (AMIGA) project, a sample consisting of the most isolated galaxies that have yet been identified. The goal is to further improve the classifications of these galaxies by examining them in the context of the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system, which includes recognition of features that go beyond the original de Vaucouleurs point of view. Our results confirm previous findings that isolated …
Multi-molecule observations towards an increasing variety of galaxies have been showing that the relative molecular abundances are affected by the type of activity. However, these studies are biased towards bright active galaxies, which are typically in interaction. We study the molecular composition of one of the most isolated galaxies in the local Universe where the physical and chemical properties of their molecular clouds have been determined by intrinsic mechanisms. We present 3 mm broad band observations of the galaxy CIG 638, extracted from the AMIGA sample of isolated galaxies. The emi…
The size of the HI disk across different environments: isolated, compact groups, clusters, and pairs
Instituto de Astrofísica de Andalucía (CSIC)（安达卢西亚天体物理研究所）；Chalmers University of Technology（查尔姆斯理工大学）；ASTRON, the Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）；Caltech（加州理工学院）；INAF – Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）
We present structural parameters and (g-i) bulge/disk colors for a large sample (189) of isolated AMIGA galaxies. The structural parameters of bulges were derived from the 2D bulge/disk/bar decomposition of SDSS i-band images using GALFIT. Galaxies were separated between classical bulges (n_b>2.5) and pseudobulges (n_b<2.5), resulting in a dominant pseudobulge population (94%) with only 12 classical bulges. In the <mu_e>-Re plane, pseudobulges are distributed below the elliptical relation (smaller Re and fainter mu_e), with the closest region to the Kormendy relation populated by those pseudob…
We present a deep search for HI 21-cm emission from the gaseous halo of Messier 31 as part of Project AMIGA, a large program Hubble Space Telescope program to study the circumgalactic medium of the Andromeda galaxy. Our observations with the Robert C. Byrd Green Bank Telesope target sight lines to 48 background AGNs, more than half of which have been observed in the ultraviolet with the Cosmic Origins Spectrograph, with impact parameters $25 \lesssim ρ\lesssim 330$ kpc ($0.1 \lesssim ρ/ R_{\rm vir} \lesssim 1.1$). We do not detect any 21-cm emission toward these AGNs to limits of $N({\rm HI}) …
The Giant Southern Stream (GSS) of M31, a keystone signature of a major accretion event, yields crucial constraints on M31 formation and evolution models. Currently, our understanding of the GSS, in terms of both its geometry and its chemistry, results from either wide-field imaging probing only a few magnitudes below the red giant branch tip, or deep imaging or spectroscopy of isolated regions. Here, we take an alternative approach, using Hubble Space Telescope (HST) imaging to characterize the horizontal branch red clump (RC) using unbinned maximum likelihood fits to luminosity functions (LF…
Project AMIGA (Absorption Maps In the Gas of Andromeda) is a large ultraviolet Hubble Space Telescope program, which has assembled a sample of 43 QSOs that pierce the circumgalactic medium (CGM) of Andromeda (M31) from R=25 to 569 kpc (25 of them probing gas from 25 kpc to about the virial radius-Rvir = 300 kpc-of M31). Our large sample provides an unparalleled look at the physical conditions and distribution of metals in the CGM of a single galaxy using ions that probe a wide range of gas phases (Si II, Si III, Si IV, C II, C IV, and O VI, the latter being from the Far Ultraviolet Spectroscop…
The galactic HI-to-halo mass relation from isolated galaxies to cosmological hydrodynamic simulations
Instituto de Astrofísica de Andalucía (CSIC)（安达卢西亚天体物理研究所）；Laboratoire de Physique et de Chimie de l’Environnement, Université Joseph Ki-Zerbo（约瑟夫·基泽尔博大学环境物理与化学实验室）；Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg（斯特拉斯堡大学）；Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi（阿布扎比纽约大学天体物理学与空间科学中心）；New York University Abu Dhabi（阿布扎比纽约大学）
We extend the analysis of Bok et al. (2020) in which the HI content of isolated galaxies from the AMIGA sample and selected paired galaxies from ALFALFA were examined as a potential driver of galaxy location on the WISE mid-infrared SFR-Mstar sequence. By further characterizing the isolated and pair galaxy samples, i.e. in terms of optical galaxy morphology, a more detailed and quantitative description of local galaxy environment by way of the local number density (eta) and tidal strength (Q) parameters, star formation efficiency (SFE(HI)), and HI integrated profile asymmetries, we present pla…
In this article, we test the conclusion of Donato et al. (2009) concerning the universality of the DM halo surface density $μ_{0D}=ρ_0r_0$. According to our study, the dispersion of values of $μ_{0D}$ is twice higher than that found by Donato et al. (2009). We conclude, in contrast with Donato et al. (2009), that the DM surface density and its Newtonian acceleration are not constant but correlate with the luminosity, morphological type, $(B-V)_0$ colour index, and the content of neutral hydrogen. These DM parameters are higher for more luminous systems of early types with red colour and low ga…
HI kinematic asymmetries are common in late-type galaxies irrespective of environment, although the amplitudes are strikingly low in isolated galaxies. As part of our studies of the HI morphology and kinematics in isolated late-type galaxies we have chosen several very isolated galaxies from the AMIGA sample for HI mapping. Here we present GMRT 21-cm HI line mapping of CIG 340 which was selected because its integrated HI spectrum has a very symmetric profile, Aflux = 1.03. Optical images of the galaxy hinted at a warped disk in contrast to the symmetric integrated HI spectrum profile. Our aim …
Isolated early-type galaxies (iETGs) are evolving in unusually poor environments for this morphological family, which is typical of cluster inhabitants. We investigate the mechanisms driving the evolution of these galaxies. Several studies indicate that interactions, accretions, and merging episodes leave their signature on the galaxy structure, from the nucleus down to the faint outskirts. We focus on revealing such signatures, if any, in a sample of iETGs, and we quantitatively revise their galaxy classification. We observed 20 (out of 104) iETGs, selected from the AMIGA catalog, with the 4K…
Asymmetries in HI in galaxies are often caused by the interaction with close companions, making isolated galaxies an ideal framework to study secular evolution. The AMIGA project has demonstrated that isolated galaxies show the lowest level of asymmetry in their HI integrated profiles, yet some present significant asymmetries. CIG 96 (NGC 864) is a representative case reaching a 16% level. Our aim is to investigate the HI asymmetries of this spiral galaxy and what processes have triggered the star-forming regions observed in the XUV pseudoring. We performed deep optical observations at CAHA 1.…
We examine the dependence between hydrogen total mass $M_{HI}$ and rotation speed $V_{rot}$, optical size $D_{25}$ or disc radial scale $R_0$ for two samples of late-type galaxies: a) isolated galaxy (AMIGA sample), and b) the edge-on galaxies (flat galaxies of Karachentsev et al. 1999). Estimates of $M_{HI}$, given in the HYPERLEDA database for flat galaxies appear to be on average higher at $\sim $0.2 dex, than for isolated galaxies with similar $V_{rot}$ or $D_{25}$ values, most probably, due to the overvaluation of self-absorption in the HI line. We confirm that the hydrogen mass for both …
We report a detection of the effect of the large-scale velocity shear on the spatial distributions of the galactic satellites around the isolated hosts. Identifying the isolated galactic systems each of which consists of a single host galaxy and its satellites from the Seventh Data Release of the Sloan Digital Sky Survey and reconstructing linearly the velocity shear field in the local universe, we measure the alignments between the relative positions of the satellites from their isolated hosts and the principal axes of the local velocity shear tensors projected on to the plane of sky. We find…
Satellites are not randomly distributed around their central galaxies but show polar and planar structures. In this paper, we investigate the axis-asymmetry or lopsidedness of satellite galaxy distributions around isolated galaxies in a hydrodynamic cosmological simulation. We find a statistically significant lopsided signal by studying the angular distribution of the satellite galaxies' projected positions around isolated central galaxies in a two-dimensional plane. The signal is dependent on galaxy mass, color and large-scale environment. Satellites that inhabit low-mass blue hosts, or locat…
We aim to identify and quantify the effects of the satellite distribution around a sample of galaxies in the Catalogue of Isolated Galaxies (CIG), as well as the effects of the Large Scale Structure (LSS) using the SDSS-DR9. To recover the physically bound galaxies we focus on the satellites which are within the escape speed of each CIG galaxy. We also propose a more conservative method using the stacked Gaussian distribution of the velocity difference of the neighbours. The tidal strengths affecting the primary galaxy are estimated to quantify the effects of the local and LSS environments. We…
The construction of catalogues of galaxies and the a posteriori study of galaxy properties in relation to their environment have been hampered by scarce redshift information. The new 3-dimensional (3D) surveys permit small, faint, physically bound satellites to be distinguished from a background-projected galaxy population. We aim to provide representative samples of isolated galaxies, isolated pairs, and isolated triplets for testing galaxy evolution and secular processes in low density regions of the local Universe, as well as to characterise their local and large-scale environments. We used…
Using an isolated Milky Way-mass galaxy simulation, we compare results from 9 state-of-the-art gravito-hydrodynamics codes widely used in the numerical community. We utilize the infrastructure we have built for the AGORA High-resolution Galaxy Simulations Comparison Project. This includes the common disk initial conditions, common physics models (e.g., radiative cooling and UV background by the standardized package Grackle) and common analysis toolkit yt, all of which are publicly available. Subgrid physics models such as Jeans pressure floor, star formation, supernova feedback energy, and met…
The present paper is devoted to the construction of a catalog of isolated galaxy pairs extracted from the HyperLEDA extragalactic database. The radial velocities of the galaxies in the pairs are in the range $[3000,16000]$ km.s$^{-1}$. In order to get an unbiased pair catalog as complete as possible, we have limited the absolute magnitude of the galaxies to $M \leq-18.5$). The criteria used to define the isolated galaxy pairs are the following: 1) Velocity criterion: radial velocity difference between the pair members $ΔV<500$ km.s$^{-1}$; 2) Interdistance criterion: projected distance between…
Galaxies have different morphology, gas content and star formation rate (SFR) in dense environments like galaxy clusters. The impact of environmental density extends to several virial radii, and galaxies are pre-processed in filaments and groups, before falling into the cluster. Our goal is to quantify this pre-processing, in terms of gas content and SFR, as a function of density in cosmic filaments. We have observed the two first CO transitions in 163 galaxies with the IRAM-30m telescope, and added 82 more measurements from the literature, for a sample of 245 galaxies in the filaments around …
The formation and evolution of elliptical galaxies in low-density environments are less understood than classical elliptical galaxies in high-density environments. Isolated galaxies are defined as galaxies without massive neighbors within scales of galaxy groups. The effect of the environment at several Mpc scales on their properties has been barely explored. Here we study the role of large-scale environment in some physical properties of 573 isolated elliptical galaxies out to z=0.08. We use three environmental estimators of the large-scale structure within a projected radius of 5 Mpc around …
Galaxy triplets are interesting laboratories where we can study the formation and the evolution of small and large systems of galaxies. This study aims to investigate signs of interaction between the members of nine isolated galaxy triplet systems (27 galaxies) selected from the "SDSS-based catalogue of Isolated Triplets" (SIT) with members brighter than 17.0 ($m_r\le$ 17.0) in the $r-$band, and mean projected separation between the members of $r_p \leq$ 0.1 Mpc. In this work, we performed a one-dimensional (1D) fitting of the surface brightness profiles and a two-dimensional (2D) modeling of …
The main goal of this study was to determine the effects on equivalent widths (EWs) of some spectral lines produced in the quasars by the presence of surrounding galaxies. To carry this out, a sample of 4663 quasars (QSOs) in the redshift range of 0.20 to 0.40 from the Sloan Digital Sky Survey--Data Release 7 was analyzed. Three QSO sub-samples were defined, taking into account the projected separations and radial velocity differences with neighboring galaxies. In this way, we utilized two sub-samples of QSOs with strong and weak galaxy interactions, with projected separations smaller than 70 …
(Abridged) We present the results of a new search for variable stars in the Local Group (LG) isolated dwarf galaxy IC1613, based on 24 orbits of F475W and F814W photometry from the ACS camera onboard the HST. We detected 259 candidate variables in this field, of which only 13 (all of them bright Cepheids) were previously known. Out of the confirmed variables, we found 90 RR Lyrae stars, 49 classical Cepheids (including 36 new discoveries), and 38 eclipsing binary stars for which we could determine a period. The RR Lyrae include 61 fundamental (RRab) and 24 first-overtone (RRc) pulsators, and 5…
We have updated the classification of late-type galaxies presented in the Catalog of Isolated Galaxies (KIG) using the advanced digital sky surveys. Our search for companions around 959 KIG galaxies revealed 141 neighbors associated with 111 KIG galaxies within the mutual projection separation of less than 330 kpc and the radial velocity difference not exceeding 500 km s$^{-1}$. Typical luminosity of the companions turned out to be weaker than the luminosity of the main galaxies by more than an order of magnitude. Considering these small companions as test particles that move around the KIG ga…
Galaxy evolution in compact groups - III. Structural analysis of galaxies and dynamical state of non-isolated compact groups
Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo（圣保罗大学地球物理与大气科学天文研究所）；CONICET, Instituto de Astronomía Teorica y Experimental (IATE)（阿根廷国家科学研究委员会理论与实验天文学研究所）；Observatorio Astronómico de Córdoba (OAC), Universidad Nacional de Córdoba (UNC)（科尔多瓦国立大学科尔多瓦天文台）；Departamento de Astronomía, Universidad de La Serena（拉塞雷纳大学天文学系）；Departamento de Tecnologías Industriales, Facultad de Ingeniería, Universidad de Talca（塔尔卡大学工程学院工业技术系）；Departamento de Física, Universidad Técnica Federico
We have used the Arecibo L-band Feed Array to map three regions, each of 5 square degrees, around the isolated galaxies NGC 1156, UGC 2082, and NGC 5523. In the vicinity of these galaxies we have detected two dwarf companions: one near UGC 2082, previously discovered by ALFALFA, and one near NGC 1156, discovered by this project and reported in an earlier paper. This is significantly fewer than the 15.4 $^{+1.7}_{-1.5}$ that would be expected from the field HI mass function from ALFALFA or the 8.9 $\pm$ 1.2 expected if the HI mass function from the Local Group applied in these regions. The numb…
The correlation between fresh gas accretion onto haloes and galaxy star formation is critical to understanding galaxy formation. Different theoretical models have predicted different correlation strengths between halo accretion rates and galaxy star formation rates, ranging from strong positive correlations to little or no correlation. Here, we present a technique to observationally measure this correlation strength for isolated Milky Way-mass galaxies with $z < 0.123$. This technique is based on correlations between dark matter accretion rates and the projected density profile of neighbouring…
Isolated massive star candidates in NGC 4242 with GULP
Gemini Observatory/NSFs NOIRLab（Gemini 天文台/美国国家光学-红外天文研究实验室）；Space Telescope Science Institute（太空望远镜科学研究所）；University of Wisconsin-Madison（威斯康星大学麦迪逊分校）；the Johns Hopkins University（约翰斯·霍普金斯大学）；Stockholm University（斯德哥尔摩大学）；University of Massachusetts Amherst（马萨诸塞大学阿默斯特分校）；Università di Pisa（比萨大学）；INFN（意大利国家核物理研究所）；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体物理学与空间科学观测站）；University of Sheffield（谢菲尔德大学）；The University of Auckland（奥克兰大学）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森尼天体物理中心）；Radcliffe Institute for Advanced Studies at Harvard University（哈佛大学拉德克利夫高等研究院）；AURA for the European Space Agency (ESA)（欧洲空间局（ESA）联盟大学研究协会）
