Cold gas and dust: Hunting spiral-like structures in early-type galaxies
M. K. Yıldız, R. F. Peletier, P. -A. Duc, P. Serra
备注：
11 pages, 7 figures, 3 tables, and 4 appendices. Appendices contain dust masses and images of studied galaxies (62). The fits files will be uploaded into the CDS database. Figures in the appendices are of low quality. High-quality images are given in a separated folder. Accepted for publication in A&A
Observations of neutral hydrogen (HI) and molecular gas show that 50% of all nearby early-type galaxies (ETGs) contain some cold gas. Molecular gas is always found in small gas discs in the central region of the galaxy, while neutral hydrogen is often distributed in a low-column density disc or ring typically extending well beyond the stellar body. Dust is frequently found in ETGs as well. The goal of our study is to understand the link between dust and cold gas in nearby ETGs as a function of HI content. We analyse deep optical $g-r$ images obtained with the MegaCam camera at the Canada-France-Hawaii Telescope for a sample of 21 HI-rich and 41 HI-poor ETGs. We find that all HI-rich galaxies contain dust seen as absorption. Moreover, in 57 percent of these HI-rich galaxies, the dust is distributed in a large-scale spiral pattern. Although the dust detection rate is relatively high in the HI-poor galaxies ($\sim$59 percent), most of these systems exhibit simpler dust morphologies without any evidence of spiral structures. We find that the HI-rich galaxies possess more complex dust morphology extending to almost two times larger radii than HI-poor objects. We measured the dust content of the galaxies from the optical colour excess and find that HI-rich galaxies contain six times more dust (in mass) than HI-poor ones. In order to maintain the dust structures in the galaxies, continuous gas accretion is needed, and the substantial HI gas reservoirs in the outer regions of ETGs can satisfy this need for a long time. We find that there is a good correspondence between the observed masses of the gas and dust, and it is also clear that dust is present in regions further than 3~Reff. Our findings indicate an essential relation between the presence of cold gas and dust in ETGs and offer a way to study the interstellar medium in more detail than what is possible with HI observations.
Spiral Morphology and Radial Migration: Kinematically heating, cooling, and cold
University of Arizona（亚利桑那大学）；Bryn Mawr College（布林莫尔学院）；University of California, Merced（加州大学默塞德分校）；Haverford College（哈弗福德学院）；Johns Hopkins University（约翰斯·霍普金斯大学）
Cosmic dust grains are one of the fundamental ingredients of the interstellar medium (ISM). In spite of their small contribution to the total mass budget, dust grains play a significant role in the physical and chemical evolution of galaxies. Over the past decades, a plethora of multi-wavelength data, from UV to far-infrared, has increased substantially our knowledge on the dust properties of nearby galaxies. Nevertheless, one regime of the spectrum, the mm range, remains relatively unexplored. Thanks to the new, high-resolution data in the mm range observed with the NIKA2 instrument and our r…
Spiral Density Waves in M81. II. Hydrodynamic Simulations for Gas Response to Stellar Spiral Density Waves
利用非磁化流体动力学模拟，探讨了M81气体对恒星螺旋的响应。约束内的不确定性的观测，18模拟进行研究的影响，自重和覆盖的参数空间，包括三个不同的声速和三个不同的臂强度。结果与波长为8 $μ$ m和21 cm的观测数据相吻合。在外盘中，在8 $μ$ m图像中观察到的环状结构与有效声速为7 km s $^{-1}$的冷中性介质的响应一致，而对于内盘，螺旋激波的存在可以理解为与有效声速为19 km s $^{-1}$的暖中性介质相关的4：1共振的结果。单一有效声速的模拟不能同时解释内外盘的结构。这证明了M81中冷、暖中性介质共存的合理性。在东北臂观察到的异常高的流运动和沿西南臂观察到的等速度线中向外移动的转折点被解释为与伴星系相互作用的特征。水平的模拟流运动缩小了观察到的手臂力量的不确定性向更大的幅度。
Tracing the dynamical and structural complexity of spiral galaxy centres
University of Vienna（维也纳大学）；Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Universidad de La Laguna（拉古纳大学）；Graduate Institute for Advanced Studies, SOKENDAI（综合研究大学院大学）；Subaru Telescope, National Astronomical Observatory of Japan（日本国立天文台 Subaru 望远镜）；Leiden University（莱顿大学）；Durham University（杜伦大学）
The formation of the red spirals is a puzzling issue in the standard picture of galaxy formation and evolution. Most studies attribute the colour of the red spirals to different environmental effects. We analyze a volume limited sample from the SDSS to study the roles of small-scale and large-scale environments on the colour of spiral galaxies. We compare the star formation rate, stellar age and stellar mass distributions of the red and blue spirals and find statistically significant differences between them at $99.9\%$ confidence level. The red spirals inhabit significantly denser regions tha…
Kinematically cold and warm planetary nebulae samples, HII regions and supernovae remnants in the disc of the face-on spiral galaxy NGC 628 (M74) -- The Planetary Nebulae Spectrograph with the H$α$ arm
ESO（欧洲南方天文台）；Max-Planck-Institüt fur Extraterrestrisches Physik（马克斯·普朗克地外物理研究所）；Research School of Astronomy and Astrophysics, Australia National University（澳大利亚国立大学天文学与天体物理学研究学院）；Oxford Astrophysics, University of Oxford（牛津大学牛津天体物理学）；Finnish Centre for Astronomy with ESO, (FINCA), University of Turku（图尔库大学芬兰ESO天文学中心）；Tuorla Observatory, Department of Physics and Astronomy, University of Turku（图尔库大学物理与天文学系图奥拉天文台）；Turku Collegium for Science, Medicine and Technology (TCSMT), University of Turku（图尔库大学科学、医学与技术学院）；School of Physics and Astronomy, University of Nottingham（诺丁汉大学物理与天文学院）；Universidade Federal do Rio de Janeiro, Observatório do Valongo（里约热内卢联邦大学瓦隆戈天文台）；Osservatorio Astronomico di Capodimonte, INAF（意大利国家天体物理研究所卡波迪蒙特天文台）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Department of Physics “E. Pancini”, University of Naples Federico II（那不勒斯斐迪南多二世大学“E.潘奇尼”物理学系）；Department of Physics and Astronomy, San Jose State University（圣何塞州立大学物理与天文学系）
Elliptical (E) and spiral (S) galaxies follow tight, but different, scaling laws that link their stellar masses, radii, and characteristic velocities. Mass and velocity, for example, scale tightly in spirals with little dependence on galaxy radius (the "Tully-Fisher relation"; TFR). On the other hand, ellipticals appear to trace a 2D surface in size-mass-velocity space (the "Fundamental Plane"; FP). Over the years, a number of studies have attempted to understand these empirical relations, usually in terms of variations of the virial theorem for E galaxies and in terms of the scaling relations…
The rotation of the galactic halos is a fascinating topic which is still waiting to be addressed. Planck data has shown the existence of a temperature asymmetry towards the halo of several nearby galaxies, such as M31, NGC 5128, M33, M81, and M82. However, the cause of this asymmetry is an open problem. A possibility to explain the observed effect relies on the presence of "cold gas clouds" populating the galactic halos, which may be the answer to the so-called missing baryon problem. Here, we present a technique to estimate an upper limit to the rotational velocity of the halo of some nearby …
In our companion paper (Brought to Light I: Michea et al. 2021), we reveal spectacular spiral galaxy-like features in deep optical imaging of nine Virgo early-type dwarf galaxies, hidden beneath a dominating smooth stellar disk. Using a new combination of approaches, we find that bar- and spiral-like features contribute 2.2-6.4% of the total flux within 2 R$_{\rm{eff}}$. In this study, we conduct high resolution simulations of cluster harassment of passive dwarf galaxies. Following close pericenter passages of the cluster core, tidal triggering generates features in our model disks that bear a…
Spiral-driven instabilities may drive gas inflow to enhance central star formation in disk galaxies. We investigate this hypothesis using the Sloan Digital Sky Survey (SDSS) in a sample of 2779 nearby unbarred star-forming main-sequence spiral galaxies. The strength of spiral arms is quantified by their average Fourier amplitude relative to the axisymmetric disk. The star formation properties in the central 1--3\,kpc region were derived from the SDSS spectra. We show that galaxies with stronger spiral arms not only tend to have more intense central specific star formation rate (sSFR), larger B…
NOEMA$^\rm{3D}$: A deep view of cold gas flows in a barred spiral galaxy at $z\sim1$
Max-Planck-Institut für Extraterrestrische Physik (MPE)（马克斯·普朗克地外物理研究所）；Max-Planck-Institut für Astrophysik (MPA)（马克斯·普朗克天体物理研究所）；University of California, Berkeley（加州大学伯克利分校）；Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文研究所）
We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hydrodynamical cosmological simulation named GARROTXA. We detect phase spirals in the vertical projection $Z- V_{Z}$ of disc's stellar particles for the first time in this type of simulations. Qualitatively similar structures were detected in the recent Gaia data, and their origin is still under study. In our model the spiral-like structures in the phase space are present in a wide range of times and locations across the disc. By accounting for an evolving mix of stellar populations, we observe that,…
We investigate the impact of spiral structure on global star formation using a sample of 2226 nearby bright disk galaxies. Examining the relationship between spiral arms, star formation rate (SFR), and stellar mass, we find that arm strength correlates well with the variation of SFR as a function of stellar mass. Arms are stronger above the star-forming galaxy main sequence (MS) and weaker below it: arm strength increases with higher $\log\,({\rm SFR}/{\rm SFR}_{\rm MS})$, where ${\rm SFR}_{\rm MS}$ is the SFR along the MS. Likewise, stronger arms are associated with higher specific SFR. We co…
Radial Distributions of Star Formation and Gas-phase Metallicity in Spiral-Elliptical Galaxy Pairs
College of Physics, Hebei Normal University（河北师范大学物理学院）；Hebei Key Laboratory of Photophysics Research and Application（河北省光物理研究与应用重点实验室）；Shijiazhuang Key Laboratory of Astronomy and Space Science（石家庄市天文与空间科学重点实验室）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Key Lab for Astrophysics, Shanghai（上海天体物理重点实验室）
Spiral Structure Properties, Dynamics, and Evolution in MW-mass Galaxy Simulations
University of California, Merced（加州大学默塞德分校）；University of Arizona（亚利桑那大学）；Observatório Nacional（国家天文台）；University of California, Davis（加州大学戴维斯分校）；University of Central Lancashire（兰开夏中央大学）；University of Washington（华盛顿大学）；Durham University（杜伦大学）
Astrophysical disks that are sufficiently cold and dense are linearly unstable to the formation of axisymmetric rings as a result of the disk's gravity. In practice, spiral structures are formed, which may in turn produce bound fragments. We study a nonlinear dynamical path that can explain the development of spirals in a local model of a gaseous disk on the subcritical side of the gravitational instability bifurcation. Axisymmetric equilibria can be radially periodic or localized, in the form of standing solitary waves. The solitary solutions have an energy slightly larger than a smooth disk.…
