GHASP: an Halpha Kinematic Survey of Spiral and Irregular Galaxies
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The HERACLES View of the H -To-HI Ratio in Galaxies
The HERACLES View of the H2-to-HI Ratio in Galaxies Adam Leroy (NRAO, Hubble Fellow) Fabian Walter, Frank Bigiel, the HERACLES and THINGS teams The Saturday Morning Summary • Star formation rate vs. gas relation on ~kpc scales breaks apart into: A relatively universal CO-SFR relation in nearby disks Systematic environmental scalings in the CO-to-HI ratio • The CO-to-HI ratio is a strong function of radius, total gas, and stellar surface density correlated with ISM properties: dust-to-gas ratio, pressure harder to link to dynamics: gravitational instability, arms • Interpretation: the CO-to-HI ratio traces the efficiency of GMC formation Density and dust can explain much of the observed behavior heracles Fabian Walter Erik Rosolowsky MPIA UBC Frank Bigiel Eva Schinnerer UC Berkeley THINGS plus… MPIA Elias Brinks Antonio Usero Gaelle Dumas U Hertfordshire OAN, Madrid MPIA Erwin de Blok Andreas Schruba Helmut Wiesemeyer U Cape Town IRAM … MPIA Rob Kennicutt Axel Weiss Karl Schuster Cambridge MPIfR IRAM Barry Madore Carsten Kramer Karin Sandstrom Carnegie IRAM MPIA Michele Thornley Daniela Calzetti Kelly Foyle Bucknell UMass MPIA Collaborators The HERA CO-Line Extragalactic Survey First maps Leroy et al. (2009) • IRAM 30m Large Program to map CO J = 2→1 line • Instrument: HERA receiver array operating at 230 GHz • 47 galaxies: dwarfs to starbursts and massive spirals -2 • Very wide-field (~ r25) and sensitive (σ ~ 1-2 Msun pc ) NGS The HI Nearby Galaxy Survey HI Walter et al. (2008), AJ Special Issue (2008) • VLA HI maps of 34 galaxies: -
High Resolution HI Distributions and Multi-Wavelength Analyses Of
High Resolution H I Distributions and Multi-Wavelength Analyses of Magellanic Spirals NGC 4618 and NGC 4625 Jane F. Kaczmarek1& Eric M. Wilcots University of Wisconsin Madison, Department of Astronomy, 475 N. Charter Street, Madison WI 53706 USA [email protected], [email protected] ABSTRACT We present a detailed analysis of high resolution H I observations of the Magellanic spiral galaxies NGC 4618 and NGC 4625. While the H I disk of NGC 4625 is remarkably quiescent with a nearly uniform velocity dispersion and no evidence of H I holes, there is a dynamic interplay between star formation and the distribution of neutral hydrogen in NGC 4618. We calculate the critical density for widespread star formation in each galaxy and find that star formation proceeds even where the surface density of the atomic gas is well below the critical density necessary for global star formation. There are strong spatial correlations in NGC 4618 between UV emission, 1.4 GHz radio continuum emission, and peaks in the H I column density. Despite the apparent overlap of the outer disks of the two galaxies, we find that they are kinematically distinct, indicating that NGC 4618 and NGC 4625 are not interacting. The structure of NGC 4618 and, in particular, the nature of its outer ring, are highly suggestive of an interaction, but the timing and nature of such an interaction remain unclear. Subject headings: galaxies: neutral hydrogen { galaxies: Magellanic spirals { galaxies: individual (NGC 4618 & NGC 4625) 1. Introduction arXiv:1206.4104v1 [astro-ph.CO] 19 Jun 2012 One of the more stunning revelations about the Local Group in the past few years has been the observations of the proper motions of the Magellanic Clouds showing that they are moving at significantly higher velocities than previously thought (e.g. -
The Professor Comet's Report Early Spring – April 2012
The Professor Comet’s Report 1 Mr. Justin J McCollum (BS, MS Physics) Lab Physics Coordinator Dept. of Physics Lamar University Welcome to the comet report which is a monthly article on the observations of comets by the amateur astronomy community and comet hunters from around the world! This C/2009 P1 Garradd with article is dedicated to the latest reports of available comets for Barred Spiral Galaxy NGC 4236 observations, current state of those comets, future 14 March 2011! predictions, & projections for observations in comet astronomy! Early Spring – April 2012 The Professor Comet’s Report 2 The Current Status of the Predominant Comets for Apr 2012! Comets Designation Orbital Magnitude Trend Observation Constellations Visibility (IAU – MPC) Status Visual (Range in (Night Sky Location) Period Lat.) Garradd 2009 P1 C 7.0* - 7.5 Fading 90°N – 30°S SW region of Ursa Major moving All Night SSW towards the SE region of Lynx. Giacobini - 21P P 9 – 10 Fading Poor N/A Zinner Elongation Lost in the daytime Glare! LINEAR 2011 F1 C 11 .7* Brightening 90°N – 20°S Undergoing retrograde motion All Night between Boötes and Draco thru the late Spring. Gehrels 2 78P P 12.2* Fading 60˚N - 20˚S Moving eastwards across Taurus Early Evening and progressing along the N edge of the Hyades Star Cluster! McNaught 2011 Q2 C 12.5 Fading 70˚N – Eqn. Currently in the S central region Early Morning of Andromeda moving NE between the boundary between Andromeda & Pisces. NEAT 246P/2010 V2 P 12.3* - 13 Possible 65˚N - 60˚S Undergoing retrograde motion All Night Steadiness in the E half of the N central region of Virgo until late June. -
Atmob Newsletterjulyfinal
expensive. I found that out when I went to Criterion Optical Co. in Hartford with a very small budget for a telescope, and the nice person I talked with finally reached into a drawer and pulled out a slightly scratched small mirror and offered it to me cheap, along STAR with a slightly defective focuser (no knob or rack, but it did have a small diagonal attached), and some miscellaneous small lenses and cardboard spacers for making an eyepiece. He also gave me FIELDS some brief verbal instructions on how to put all this together into a Newtonian telescope. Next stop the hardware store to buy a piece of stove pipe, and I was in business after a little construction work. There were no astronomy books in our local Newsletter of the library, but just sweeping the dark sky (back then it was dark) and Amateur Telescope Makers of Boston picking out some interesting sights – even with no idea what they Including the Bond Astronomical Club were or what they were called - was a thrill for a teenager. Established in 1934 In the Interest of Telescope Making & Using It would be nice if I could tell you that I stayed with the hobby continuously from then up to now. But the truth is that other Vol. 22, No. 7 July 2010 things- college, grad school and then the “real world”- soon intervened and demanded attention and my astronomy activities faded into the past. This Month’s Meeting… th Then for my birthday about ten years ago- out of the blue and Thursday, July 8 , 2010 at 8:00 PM with no warning- my wife and two boys decided to give me a Phillips Auditorium telescope. -
Arxiv:0907.4718V1 [Astro-Ph.GA] 27 Jul 2009 Nnab Aais Hi Ihlmnste ( Luminosities High Their Objects Point-Like Galaxies
Submitted to Astrophysical Journal A Preprint typeset using L TEX style emulateapj v. 04/03/99 ULTRALUMINOUS X-RAY SOURCE CORRELATIONS WITH STAR-FORMING REGIONS Douglas A. Swartz1 Allyn F. Tennant2, and Roberto Soria3 Submitted to Astrophysical Journal ABSTRACT Maps of low-inclination nearby galaxies in Sloan Digitized Sky Survey u − g, g − r and r − i colors are used to determine whether Ultraluminous X-ray sources (ULXs) are predominantly associated with star-forming regions of their host galaxies. An empirical selection criterion is derived from colors of H ii regions in M 81 and M 101 that differentiates between the young, blue stellar component and the older disk and bulge population. This criterion is applied to a sample of 58 galaxies of Hubble type S0 and later and verified through an application of Fisher’s linear discriminant analysis. It is found that 60% (49%) of ULXs in optically-bright environments are within regions blueward of their host galaxy’s H ii regions compared to only 27% (0%) of a control sample according to the empirical (Fisher) criterion. This is an excess of 3σ above the 32% (27%) expected if the ULXs were randomly distributed within their galactic hosts. This indicates a ULX preference for young, ∼<10 Myr, OB associations. However, none of the ULX environments have the morphology and optical brightness suggestive of a massive young super star cluster though several are in extended or crowded star-forming (blue) environments that may contain clusters unresolved by Sloan imaging. Ten of the 12 ULX candidates with estimated X-ray luminosities in excess of 3×1039 ergs s−1 are equally divided among the group of ULX environments redward of H ii regions and the group of optically faint regions. -
Mandm Direct Spreads
Touring the moonlit Spring Skies... Observations from Saturday 11th May 2019 8.30pm - 2.15am Equipment used: TEC 140, tracking Nova Hitch Alt-Az with slow-mo controls and encoders on a Berlebach Planet, iPad Air2 running SkySafari Pro 5, Nexus WiFi, 10 and 21mm Ethos, Baader BBHS diagonal, Lumicon 2” UHC and OIII filters in a True-Tech manual filter wheel. Mixed forecasts, Clear Outside suggesting 27% cloud around midnight, Xasteria saying clear, Clear Outside loaded from within Xasteria offering something in-between (how do you get that, hey!?) and Meteoblue forecasting clear skies from 11 but with poor ‘Index 2’ and Jet Stream readings.... Having neglected visual astronomy for many months (having spent my time finally getting the imaging gear to play ball), I spent forty odd minutes re-learning how to set everything back up - in fact, it be on offer with the moon in attendance... took longer than it does to wheel out the imaging gear. Times have changed, my usual (100% visual) observing buddy was having a go at imaging (spectroscopy), so I was on my own for this evening. It meant I’d have to keep my own notes for a change, but also allow me to go at my own pace as I reacquainted myself with the night sky. By 8.30 I was ready to go, clear skies, still a shade of blue with a half moon hanging over in the south western sky. Temperature rapidly dropping. 21mm eyepiece in place easily held the entire moon. Fantastic details, sharp, contrasty, zero colour.. -
The Low-Metallicity Picture A
Linking dust emission to fundamental properties in galaxies: the low-metallicity picture A. Rémy-Ruyer, S. C. Madden, F. Galliano, V. Lebouteiller, M. Baes, G. J. Bendo, A. Boselli, L. Ciesla, D. Cormier, A. Cooray, et al. To cite this version: A. Rémy-Ruyer, S. C. Madden, F. Galliano, V. Lebouteiller, M. Baes, et al.. Linking dust emission to fundamental properties in galaxies: the low-metallicity picture. Astronomy and Astrophysics - A&A, EDP Sciences, 2015, 582, pp.A121. 10.1051/0004-6361/201526067. cea-01383748 HAL Id: cea-01383748 https://hal-cea.archives-ouvertes.fr/cea-01383748 Submitted on 19 Oct 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A&A 582, A121 (2015) Astronomy DOI: 10.1051/0004-6361/201526067 & c ESO 2015 Astrophysics Linking dust emission to fundamental properties in galaxies: the low-metallicity picture? A. Rémy-Ruyer1;2, S. C. Madden2, F. Galliano2, V. Lebouteiller2, M. Baes3, G. J. Bendo4, A. Boselli5, L. Ciesla6, D. Cormier7, A. Cooray8, L. Cortese9, I. De Looze3;10, V. Doublier-Pritchard11, M. Galametz12, A. P. Jones1, O. Ł. Karczewski13, N. Lu14, and L. Spinoglio15 1 Institut d’Astrophysique Spatiale, CNRS, UMR 8617, 91405 Orsay, France e-mail: [email protected]; [email protected] 2 Laboratoire AIM, CEA/IRFU/Service d’Astrophysique, Université Paris Diderot, Bât. -
Hubble's Cosmic Search for a Missing Arm 20 November 2017
Image: Hubble's cosmic search for a missing arm 20 November 2017 They speculated that NGC 4618 may be the culprit "harassing" NGC 4625, causing it to lose all but one spiral arm. In 2004 astronomers found proof for this claim. The gas in the outermost regions of the dwarf galaxy NGC 4618 has been strongly affected by NGC 4625. Provided by NASA Credit: ESA/Hubble & NASA This new picture of the week, taken by the NASA/ESA Hubble Space Telescope, shows the dwarf galaxy NGC 4625, located about 30 million light-years away in the constellation of Canes Venatici (The Hunting Dogs). The image, acquired with the Advanced Camera for Surveys (ACS), reveals the single major spiral arm of the galaxy, which gives it an asymmetric appearance. But why is there only one such spiral arm, when spiral galaxies normally have at least two? Astronomers looked at NGC 4625 in different wavelengths in the hope of solving this cosmic mystery. Observations in the ultraviolet provided the first hint: in ultraviolet light the disk of the galaxy appears four times larger than on the image depicted here. An indication that there are a large number of very young and hot—hence mainly visible in the ultraviolet—stars forming in the outer regions of the galaxy. These young stars are only around one billion years old, about 10 times younger than the stars seen in the optical center. At first astronomers assumed that this high star formation rate was being triggered by the interaction with another, nearby dwarf galaxy called NGC 4618. -
00E the Construction of the Universe Symphony
The basic construction of the Universe Symphony. There are 30 asterisms (Suites) in the Universe Symphony. I divided the asterisms into 15 groups. The asterisms in the same group, lay close to each other. Asterisms!! in Constellation!Stars!Objects nearby 01 The W!!!Cassiopeia!!Segin !!!!!!!Ruchbah !!!!!!!Marj !!!!!!!Schedar !!!!!!!Caph !!!!!!!!!Sailboat Cluster !!!!!!!!!Gamma Cassiopeia Nebula !!!!!!!!!NGC 129 !!!!!!!!!M 103 !!!!!!!!!NGC 637 !!!!!!!!!NGC 654 !!!!!!!!!NGC 659 !!!!!!!!!PacMan Nebula !!!!!!!!!Owl Cluster !!!!!!!!!NGC 663 Asterisms!! in Constellation!Stars!!Objects nearby 02 Northern Fly!!Aries!!!41 Arietis !!!!!!!39 Arietis!!! !!!!!!!35 Arietis !!!!!!!!!!NGC 1056 02 Whale’s Head!!Cetus!! ! Menkar !!!!!!!Lambda Ceti! !!!!!!!Mu Ceti !!!!!!!Xi2 Ceti !!!!!!!Kaffalijidhma !!!!!!!!!!IC 302 !!!!!!!!!!NGC 990 !!!!!!!!!!NGC 1024 !!!!!!!!!!NGC 1026 !!!!!!!!!!NGC 1070 !!!!!!!!!!NGC 1085 !!!!!!!!!!NGC 1107 !!!!!!!!!!NGC 1137 !!!!!!!!!!NGC 1143 !!!!!!!!!!NGC 1144 !!!!!!!!!!NGC 1153 Asterisms!! in Constellation Stars!!Objects nearby 03 Hyades!!!Taurus! Aldebaran !!!!!! Theta 2 Tauri !!!!!! Gamma Tauri !!!!!! Delta 1 Tauri !!!!!! Epsilon Tauri !!!!!!!!!Struve’s Lost Nebula !!!!!!!!!Hind’s Variable Nebula !!!!!!!!!IC 374 03 Kids!!!Auriga! Almaaz !!!!!! Hoedus II !!!!!! Hoedus I !!!!!!!!!The Kite Cluster !!!!!!!!!IC 397 03 Pleiades!! ! Taurus! Pleione (Seven Sisters)!! ! ! Atlas !!!!!! Alcyone !!!!!! Merope !!!!!! Electra !!!!!! Celaeno !!!!!! Taygeta !!!!!! Asterope !!!!!! Maia !!!!!!!!!Maia Nebula !!!!!!!!!Merope Nebula !!!!!!!!!Merope -
Arxiv:1007.4547V2 [Astro-Ph.CO]
ApJS, in press Preprint typeset using LATEX style emulateapj v. 11/10/09 OPTICAL SPECTROSCOPY AND NEBULAR OXYGEN ABUNDANCES OF THE SPITZER/SINGS GALAXIES John Moustakas1, Robert C. Kennicutt, Jr.2,3, Christy A. Tremonti4, Daniel A. Dale5, John-David T. Smith6, Daniela Calzetti7 ApJS, in press ABSTRACT We present intermediate-resolution optical spectrophotometry of 65 galaxies obtained in support of the Spitzer Infrared Nearby Galaxies Survey (SINGS). For each galaxy we obtain a nuclear, circumnu- clear, and semi-integrated optical spectrum designed to coincide spatially with mid- and far-infrared spectroscopy from the Spitzer Space Telescope. We make the reduced, spectrophotometrically cali- brated one-dimensional spectra, as well as measurements of the fluxes and equivalent widths of the strong nebular emission lines, publically available. We use optical emission-line ratios measured on all three spatial scales to classify the sample into star-forming, active galactic nuclei (AGN), and galaxies with a mixture of star formation and nuclear activity. We find that the relative fraction of the sample classified as star-forming versus AGN is a strong function of the integrated light enclosed by the spec- troscopic aperture. We supplement our observations with a large database of nebular emission-line measurements of individual H ii regions in the SINGS galaxies culled from the literature. We use these ancillary data to conduct a detailed analysis of the radial abundance gradients and average H ii- region abundances of a large fraction of the sample. We combine these results with our new integrated spectra to estimate the central and characteristic (globally-averaged) gas-phase oxygen abundances of all 75 SINGS galaxies. -
Hercules a Monthly Sky Guide for the Beginning to Intermediate Amateur Astronomer Tom Trusock - 7/09
Small Wonders: Hercules A monthly sky guide for the beginning to intermediate amateur astronomer Tom Trusock - 7/09 Dragging forth the summer Milky Way, legendary strongman Hercules is yet another boundary constellation for the summer season. His toes are dipped in the stream of our galaxy, his head is firm in the depths of space. Hercules is populated by a dizzying array of targets, many extra-galactic in nature. Galaxy clusters abound and there are three Hickson objects for the aficionado. There are a smattering of nice galaxies, some planetary nebulae and of course a few very nice globular clusters. 2/19 Small Wonders: Hercules Widefield Finder Chart - Looking high and south, early July. Tom Trusock June-2009 3/19 Small Wonders: Hercules For those inclined to the straightforward list approach, here's ours for the evening: Globular Clusters M13 M92 NGC 6229 Planetary Nebulae IC 4593 NGC 6210 Vy 1-2 Galaxies NGC 6207 NGC 6482 NGC 6181 Galaxy Groups / Clusters AGC 2151 (Hercules Cluster) Tom Trusock June-2009 4/19 Small Wonders: Hercules Northern Hercules Finder Chart Tom Trusock June-2009 5/19 Small Wonders: Hercules M13 and NGC 6207 contributed by Emanuele Colognato Let's start off with the masterpiece and work our way out from there. Ask any longtime amateur the first thing they think of when one mentions the constellation Hercules, and I'd lay dollars to donuts, you'll be answered with the globular cluster Messier 13. M13 is one of the easiest objects in the constellation to locate. M13 lying about 1/3 of the way from eta to zeta, the two stars that define the westernmost side of the keystone. -
Gas Accretion from Minor Mergers in Local Spiral Galaxies⋆
A&A 567, A68 (2014) Astronomy DOI: 10.1051/0004-6361/201423596 & c ESO 2014 Astrophysics Gas accretion from minor mergers in local spiral galaxies? E. M. Di Teodoro1 and F. Fraternali1;2 1 Department of Physics and Astronomy, University of Bologna, 6/2, Viale Berti Pichat, 40127 Bologna, Italy e-mail: [email protected] 2 Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen, The Netherlands Received 7 February 2014 / Accepted 28 May 2014 ABSTRACT We quantify the gas accretion rate from minor mergers onto star-forming galaxies in the local Universe using Hi observations of 148 nearby spiral galaxies (WHISP sample). We developed a dedicated code that iteratively analyses Hi data-cubes, finds dwarf gas-rich satellites around larger galaxies, and estimates an upper limit to the gas accretion rate. We found that 22% of the galaxies have at least one detected dwarf companion. We made the very stringent assumption that all satellites are going to merge in the shortest possible time, transferring all their gas to the main galaxies. This leads to an estimate of the maximum gas accretion rate of −1 0.28 M yr , about five times lower than the average star formation rate of the sample. Given the assumptions, our accretion rate is clearly an overestimate. Our result strongly suggests that minor mergers do not play a significant role in the total gas accretion budget in local galaxies. Key words. galaxies: interactions – galaxies: evolution – galaxies: kinematics and dynamics – galaxies: star formation – galaxies: dwarf 1. Introduction structures in the Universe grow by several inflowing events and have increased their mass content through a small number of The evolution of galaxies is strongly affected by their capabil- major mergers, more common at high redshifts, and through an ity of retaining their gas and accreting fresh material from the almost continuous infall of dwarf galaxies (Bond et al.