Star Forming Regions in Cepheus
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Filter Performance Comparisons for Some Common Nebulae
Filter Performance Comparisons For Some Common Nebulae By Dave Knisely Light Pollution and various “nebula” filters have been around since the late 1970’s, and amateurs have been using them ever since to bring out detail (and even some objects) which were difficult to impossible to see before in modest apertures. When I started using them in the early 1980’s, specific information about which filter might work on a given object (or even whether certain filters were useful at all) was often hard to come by. Even those accounts that were available often had incomplete or inaccurate information. Getting some observational experience with the Lumicon line of filters helped, but there were still some unanswered questions. I wondered how the various filters would rank on- average against each other for a large number of objects, and whether there was a “best overall” filter. In particular, I also wondered if the much-maligned H-Beta filter was useful on more objects than the two or three targets most often mentioned in publications. In the summer of 1999, I decided to begin some more comprehensive observations to try and answer these questions and determine how to best use these filters overall. I formulated a basic survey covering a moderate number of emission and planetary nebulae to obtain some statistics on filter performance to try to address the following questions: 1. How do the various filter types compare as to what (on average) they show on a given nebula? 2. Is there one overall “best” nebula filter which will work on the largest number of objects? 3. -
Metallicities of the Β Cephei Stars from Low-Resolution Ultraviolet Spectra
A&A 433, 659–669 (2005) Astronomy DOI: 10.1051/0004-6361:20040396 & c ESO 2005 Astrophysics Metallicities of the β Cephei stars from low-resolution ultraviolet spectra E. Niemczura and J. Daszynska-Daszkiewicz´ Astronomical Institute, Wrocław University, ul. Kopernika 11, 51-622 Wrocław, Poland e-mail: [email protected] Received 5 March 2004 / Accepted 22 November 2004 Abstract. We derive basic stellar parameters (angular diameters, effective temperatures, metallicities) and interstellar reddening for all β Cephei stars observed during the IUE satellite mission, including those belonging to three open clusters. The parameters are derived by means of an algorithmic procedure of fitting theoretical flux distributions to the low-resolution IUE spectra and ground-based spectrophotometric observations. Since the metallicity has a special importance for pulsating B-type stars, we focus our attention in particular on this parameter. Key words. stars: early-type – stars: abundances – stars: variables: general 1. Introduction In this paper we analyze the IUE (International Ultraviolet Explorer) data combined with ground-based spectrophotomet- β Cephei variables are a well-known group of early B-type ric observations of β Cephei stars. The ultraviolet (UV) part pulsating stars. Their pulsations are driven by the classical of the spectra of main-sequence B-type stars is very rich in κ-mechanism, operating in the layer of the metal opacity bump lines of the iron-group elements. Because the greatest amount ≈ × 5 at T 2 10 K caused by the large number of absorption of energy for these objects is emitted in the spectral region be- lines of the iron-group elements. -
Správa O Činnosti Organizácie SAV Za Rok 2017
Astronomický ústav SAV Správa o činnosti organizácie SAV za rok 2017 Tatranská Lomnica január 2018 Obsah osnovy Správy o činnosti organizácie SAV za rok 2017 1. Základné údaje o organizácii 2. Vedecká činnosť 3. Doktorandské štúdium, iná pedagogická činnosť a budovanie ľudských zdrojov pre vedu a techniku 4. Medzinárodná vedecká spolupráca 5. Vedná politika 6. Spolupráca s VŠ a inými subjektmi v oblasti vedy a techniky 7. Spolupráca s aplikačnou a hospodárskou sférou 8. Aktivity pre Národnú radu SR, vládu SR, ústredné orgány štátnej správy SR a iné organizácie 9. Vedecko-organizačné a popularizačné aktivity 10. Činnosť knižnično-informačného pracoviska 11. Aktivity v orgánoch SAV 12. Hospodárenie organizácie 13. Nadácie a fondy pri organizácii SAV 14. Iné významné činnosti organizácie SAV 15. Vyznamenania, ocenenia a ceny udelené organizácii a pracovníkom organizácie SAV 16. Poskytovanie informácií v súlade so zákonom o slobodnom prístupe k informáciám 17. Problémy a podnety pre činnosť SAV PRÍLOHY A Zoznam zamestnancov a doktorandov organizácie k 31.12.2017 B Projekty riešené v organizácii C Publikačná činnosť organizácie D Údaje o pedagogickej činnosti organizácie E Medzinárodná mobilita organizácie F Vedecko-popularizačná činnosť pracovníkov organizácie SAV Správa o činnosti organizácie SAV 1. Základné údaje o organizácii 1.1. Kontaktné údaje Názov: Astronomický ústav SAV Riaditeľ: Mgr. Martin Vaňko, PhD. Zástupca riaditeľa: Mgr. Peter Gömöry, PhD. Vedecký tajomník: Mgr. Marián Jakubík, PhD. Predseda vedeckej rady: RNDr. Luboš Neslušan, CSc. Člen snemu SAV: Mgr. Marián Jakubík, PhD. Adresa: Astronomický ústav SAV, 059 60 Tatranská Lomnica http://www.ta3.sk Tel.: 052/7879111 Fax: 052/4467656 E-mail: [email protected] Názvy a adresy detašovaných pracovísk: Astronomický ústav - Oddelenie medziplanetárnej hmoty Dúbravská cesta 9, 845 04 Bratislava Vedúci detašovaných pracovísk: Astronomický ústav - Oddelenie medziplanetárnej hmoty prof. -
Successful Observing Sessions HOWL-EEN FUN Kepler’S Supernova Remnant Harvard’S Plate Project and Women Computers
Published by the Astronomical League Vol. 69, No. 4 September 2017 Successful Observing Sessions HOWL-EEN FUN Kepler’s Supernova Remnant Harvard’s Plate Project and Women Computers T HE ASTRONOMICAL LEAGUE 1 he 1,396th entry in John the way to HR 8281, is the Dreyer’s Index Catalogue of Elephant’s Trunk Nebula. The T Nebulae and Clusters of left (east) edge of the trunk Stars is associated with a DEEP-SKY OBJECTS contains bright, hot, young galactic star cluster contained stars, emission nebulae, within a large region of faint reflection nebulae, and dark nebulosity, and a smaller region THE ELEPHANT’S TRUNK NEBULA nebulae worth exploring with an within it called the Elephant’s 8-inch or larger telescope. Trunk Nebula. In general, this By Dr. James R. Dire, Kauai Educational Association for Science & Astronomy Other features that are an entire region is absolute must to referred to by the check out in IC pachyderm 1396 are the proboscis phrase. many dark IC 1396 resides nebulae. Probably in the constellation the best is Cepheus and is Barnard 161. This located 2,400 light- dark nebula is years from Earth. located 15 To find IC 1396, arcminutes north start at Alpha of SAO 33652. Cephei, a.k.a. The nebula Alderamin, and go measures 5 by 2.5 five degrees arcminutes in southeast to the size. The nebula is fourth-magnitude very dark. Myriad red star Mu Cephei. Milky Way stars Mu Cephei goes by surround the the Arabic name nebula, but none Erakis. It is also can be seen in called Herschel’s this small patch of Garnet Star, after the sky. -
Wynyard Planetarium & Observatory a Autumn Observing Notes
Wynyard Planetarium & Observatory A Autumn Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn Tour of the Sky with the Naked Eye CASSIOPEIA Look for the ‘W’ 4 shape 3 Polaris URSA MINOR Notice how the constellations swing around Polaris during the night Pherkad Kochab Is Kochab orange compared 2 to Polaris? Pointers Is Dubhe Dubhe yellowish compared to Merak? 1 Merak THE PLOUGH Figure 1: Sketch of the northern sky in autumn. © Rob Peeling, CaDAS, 2007 version 1.2 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. Close to the horizon is a group of stars like the outline of a saucepan with the handle stretching to your left. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The two right-hand stars are called the Pointers. Can you tell that the higher of the two, Dubhe is slightly yellowish compared to the lower, Merak? Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white- hot. 2. Use the Pointers to guide you upwards to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the left are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris. -
Scutum Apus Aquarius Aquila Ara Bootes Canes Venatici Capricornus Centaurus Cepheus Circinus Coma Berenices Corona Austrina Coro
Polaris Ursa Minor Cepheus Camelopardus Thuban Draco Cassiopeia Mizar Ursa Major Lacerta Lynx Deneb Capella Perseus Auriga Canes Venatici Algol Cygnus Vega Cor Caroli Andromeda Lyra Bootes Leo Minor Castor Triangulum Corona Borealis Albireo Hercules Pollux Alphecca Gemini Vulpecula Coma Berenices Pleiades Aries Pegasus Sagitta Arcturus Taurus Cancer Aldebaran Denebola Leo Delphinus Serpens [Caput] Regulus Equuleus Altair Canis Minor Pisces Betelgeuse Aquila Procyon Orion Serpens [Cauda] Ophiuchus Virgo Sextans Monoceros Mira Scutum Rigel Aquarius Spica Cetus Libra Crater Capricornus Hydra Sirius Corvus Lepus Deneb Kaitos Canis Major Eridanus Antares Fomalhaut Piscis Austrinus Sagittarius Scorpius Antlia Pyxis Fornax Sculptor Microscopium Columba Caelum Corona Austrina Lupus Puppis Grus Centaurus Vela Norma Horologium Phoenix Telescopium Ara Canopus Indus Crux Pictor Achernar Hadar Carina Dorado Tucana Circinus Rigel Kentaurus Reticulum Pavo Triangulum Australe Musca Volans Hydrus Mensa Apus SampleOctans file Chamaeleon AND THE LONELY WAR Sample file STAR POWER VOLUME FOUR: STAR POWER and the LONELY WAR Copyright © 2018 Michael Terracciano and Garth Graham. All rights reserved. Star Power, the Star Power logo, and all characters, likenesses, and situations herein are trademarks of Michael Terracciano and Garth Graham. Except for review purposes, no portion of this publication may be reproduced or transmitted, in any form or by any means, without the express written consent of the copyright holders. All characters and events in this publication are fictional and any resemblance to real people or events is purely coincidental. Star chartsSample adapted from charts found at hoshifuru.jp file Portions of this book are published online at www.starpowercomic.com. This volume collects STAR POWER and the LONELY WAR Issues #16-20 published online between Oct 2016 and Oct 2017. -
On the Detection of Exoplanets Via Radial Velocity Doppler Spectroscopy
The Downtown Review Volume 1 Issue 1 Article 6 January 2015 On the Detection of Exoplanets via Radial Velocity Doppler Spectroscopy Joseph P. Glaser Cleveland State University Follow this and additional works at: https://engagedscholarship.csuohio.edu/tdr Part of the Astrophysics and Astronomy Commons How does access to this work benefit ou?y Let us know! Recommended Citation Glaser, Joseph P.. "On the Detection of Exoplanets via Radial Velocity Doppler Spectroscopy." The Downtown Review. Vol. 1. Iss. 1 (2015) . Available at: https://engagedscholarship.csuohio.edu/tdr/vol1/iss1/6 This Article is brought to you for free and open access by the Student Scholarship at EngagedScholarship@CSU. It has been accepted for inclusion in The Downtown Review by an authorized editor of EngagedScholarship@CSU. For more information, please contact [email protected]. Glaser: Detection of Exoplanets 1 Introduction to Exoplanets For centuries, some of humanity’s greatest minds have pondered over the possibility of other worlds orbiting the uncountable number of stars that exist in the visible universe. The seeds for eventual scientific speculation on the possibility of these "exoplanets" began with the works of a 16th century philosopher, Giordano Bruno. In his modernly celebrated work, On the Infinite Universe & Worlds, Bruno states: "This space we declare to be infinite (...) In it are an infinity of worlds of the same kind as our own." By the time of the European Scientific Revolution, Isaac Newton grew fond of the idea and wrote in his Principia: "If the fixed stars are the centers of similar systems [when compared to the solar system], they will all be constructed according to a similar design and subject to the dominion of One." Due to limitations on observational equipment, the field of exoplanetary systems existed primarily in theory until the late 1980s. -
物理雙月刊29-3 621-772.Pdf
ᒳृݧ ʳ ౨ᄭઝݾറᙀ ᚮࣔᏕ/֮ ΔࢨუԵᛵᇞݺଚشଶಬߨጿጿլឰऱਞ ၦऱࠌ ౨ᄭऱ࣠Δኙ٤شॸΔ᠏ณհၴԾࠩԱքΕԮִ መ৫ࠌ ഏᎾၴऱڇऱᐙګԳพஒऱ ᛩቼࢬທח᥆࣍ङऱֲΔ עء۶ΔլោᥦԫՀڕټᚰۖࠐΖ ඈچᑷԫंंլឰ Δᑷ รԼᒧറ֮ΚψൕഏᎾᛩቼਐᑇࡌ௧ᛩ៥ऱ ऱ࿇ሽ౨ᄭऱᛘΔ ֗ IEA อૠװထԫैཀհլ݈ ωΔᇠᒧ֮ີტխᘋՕᖂ܉ऱՕհխΔᨃԳ ։ᗺ៥࣍ ᤚຑ़Εຑ௧ຟआᤴ ढߓ୪ւࣳඒ࣍ඒᖂઔߒ խࢼ़ݺଚᐷᐊΖڦۍऱ ᎩհᎾΔڼԱΖՈࠌଖ ᆖᛎࡉഏԺऱ࿇୶זᆏᆏՂ چሽլឰشڞऱ ᎅ࠷ެ࣍౨ᄭױሽ ፖᑓΔ༓شڇΔኚ໌ΖྥۖΔ֒ Δޡݾऱၞشࠡሎ֗شழΔݺଚՈՕ ऱࠌٵཚऱ ᎅਢԫഏᆖᛎ࿇୶ऱױCO2 ऱඈ࣋ၦࡉᄵயᚨ ౨ᄭ ٺΔ౨ᄭᤜᠲኙ࣍ڼڂऱ༞֏ΔထኔఎՀԱլ֟լߜ ೯ԺΖ ࡳࢤެڶᏆऱ࿇୶ࠠٺڇᄊ֏ ഏچຒףԱګऱધᙕΔՈ ߪᣂএࠩԫषᄎՕฒऱ壂ઘࡉֲൄढ֊ޓயᚨऱං֫հԫΖ ऱᐙΔ ฒاڇवኙ࣍ Ꮭऱं೯ΖᅝഏᎾईᏝՂཆΔഏփढᏝঁஓஓױݺଚࠆ࠹ԫաऱ堚ළፖঁ൸հᎾΔڇ ՂይΖچΔ ऱৼᜢխᆥྤݲᐫᇷᄭᤖ៲ຆΔ౨ᄭ༓٤ᑇٛᘸၞՑऱྥ֚ 9 ڣ ࣍ 2005ޓࠐΔईᏝᆏᆏ֒Δڣၦথբ २༓شࢬऱؓ݁ሽၦࡉ౨ᄭࠌڣޢԳޢݺଚ ද࣍ US$70 ऱ໌ޢࠐऱᖵᄅΔሒڣۍሽ ִٝડధڇ౨ᄭΕڇऱছૄΜૉ൞უڇټਢඈ ᄭ۞ᖏञࡉైڂຝ։ڶᄅધᙕΖईᏝऱं೯ឈ ᚮࣔᏕ ౨ᄭفՂ֏چլ؆ਢڂԫ܀ਙएࠃٙΔ 堚ဎՕᖂढߓمഏ ڶईΕ֚ྥࡉᅁ౨ᄭᗏற)ऱᤖ៲ၦึߒفऑਐ) E-mail: [email protected] ࢤΔૉشऱ౨ᄭࠌڶૻΖറ୮ေ۷ૉᖕԳᣊ Ϯ621Ϯʳ քִʳڣ ˊ˃˃˅ʻ֥࠴Կཚʼʳעढᠨִ ᒳृݧ ༚ྼऱႨΖᅝᓫᓵᇠ֘ுΛࢨਢᇠᖑுΛംᠲڶۖ ࠩބயऱᆏ౨ֱூΔࢨլᕣݶ༈ڶإటנ༼౨آᙈᙈ ᇞு౨ᗏறऱ፹ທመچհছΔषᄎՕฒᚨᇠ٣堚ᄑ ڶՂೈᅁᇷᄭࡸچ౨ᄭऱᇩΔঞזࠠயհཙ ؆ਜ਼ழऱۆுᘿ୴֗אΔ܂࿓ࡉு౨࿇ሽऱՠ فईࡉ֚ྥ֏فڕהऱᤖ៲ၦ؆Δࠡ׳ؐڣ 200 ࢤড়ᨠऱኪ৫אթ౨ڼڕୌࠄΔڶՂऱ ᥨൻਜࠩࢍאڣ ౨ྤऄ֭ᐶመ 50ױၦቃ۷ژᗏறऱᚏ ཚءΔڼڂᖗΖހᒔऱإԫנு౨࿇ሽشࠌܡၦΖ ਢޣ౨ᄭ᜔Ꮑ ሽֆுԿᐗૠቤิ९ದ໑Փऱᑷ֧֨ᗏ ܑຘመف᠏ངயለհႚอ֏܅ءګΔᆖᛎۖྥ ሽֆு౨࿇ሽኔ೭ᆖ᧭ऱڣڍڶࠩԱٍࠠބऱሽ౨ Δشऴ൷ࠌאԫՕฒګ᠏ངڇΔشறऱࠌ ،ݺଚ֮റ૪ψࢢسࢨᑷ౨ऱመ࿓խΔᄎ ு֨ᛜሎᓰᓰ९׆ᐚᆠ٣(شԺ࿇ሽ)Ε೯౨(ሎᙁ־อጠ) ॺൄ᧩࣐ᚩऱאԱᇞ،--ு౨࿇ሽᓫωΔᇠ֮ڕլ ۆᎨॸΔᖄીᣤૹऱᛩቼګඈ࣋Օၦऱᄵ᧯ࡉݮ ຝٺᎅࣔԱு౨࿇ሽऱچᦰृ堚ᄑڗऱؓ݁ᄵ৫ 壄֮چࡉֲᣤૹऱᄵயᚨΔၞۖᖄી ኪؓᘝ ੌ࿓ࡉுᗏறՄऱ፹ທመ࿓Δਢԫᒧॺൄଖԫᦰऱسऱڶऱ۞ྥᛩቼࡉچኙۖڂດዬՂ֒Ζ ኪᛩቼ૿ ֮ີΖسऱچऱᣤૹᓢᚰΔࠌڃனױլګؘലທ ٤ᤜᠲǵഏᎾईᏝࡺլڜईفᜯ؎ՕऱਗᖏΖ ࠹ࠩ٤ ՂഏᎾၴᒤᄵ᧯ඈ࣋྇ၦࢭᘭհᛩঅֆףࡉଢऱ᧢ᔢࢬທ ՀΔ᧢ޏኙᛩቼऱشᣂ౨ᄭሎڶ ڂᛩঅრᢝይ֗אඔ೯ΔڤإऱᐙຍଡૹᤜᠲΔݺଚܑࡡᓮՠᄐݾઔߒ પψࠇຟᤜࡳωګ ԳᣊؘߨհሁΖ۶ᘯګ౨ᄭسᡖᐚ ైऱᓢᚰՀΔං೯٦ۂ(Հ១ጠՠઔೃ౨ᛩࢬא)ೃ౨ᄭፖᛩቼઔߒࢬ ౨ᄭ࿇ሽωٍᆖسรքᒧറ֮ψ٦עء౨ᄭΛس٦ -
Astronomy 2008 Index
Astronomy Magazine Article Title Index 10 rising stars of astronomy, 8:60–8:63 1.5 million galaxies revealed, 3:41–3:43 185 million years before the dinosaurs’ demise, did an asteroid nearly end life on Earth?, 4:34–4:39 A Aligned aurorae, 8:27 All about the Veil Nebula, 6:56–6:61 Amateur astronomy’s greatest generation, 8:68–8:71 Amateurs see fireballs from U.S. satellite kill, 7:24 Another Earth, 6:13 Another super-Earth discovered, 9:21 Antares gang, The, 7:18 Antimatter traced, 5:23 Are big-planet systems uncommon?, 10:23 Are super-sized Earths the new frontier?, 11:26–11:31 Are these space rocks from Mercury?, 11:32–11:37 Are we done yet?, 4:14 Are we looking for life in the right places?, 7:28–7:33 Ask the aliens, 3:12 Asteroid sleuths find the dino killer, 1:20 Astro-humiliation, 10:14 Astroimaging over ancient Greece, 12:64–12:69 Astronaut rescue rocket revs up, 11:22 Astronomers spy a giant particle accelerator in the sky, 5:21 Astronomers unearth a star’s death secrets, 10:18 Astronomers witness alien star flip-out, 6:27 Astronomy magazine’s first 35 years, 8:supplement Astronomy’s guide to Go-to telescopes, 10:supplement Auroral storm trigger confirmed, 11:18 B Backstage at Astronomy, 8:76–8:82 Basking in the Sun, 5:16 Biggest planet’s 5 deepest mysteries, The, 1:38–1:43 Binary pulsar test affirms relativity, 10:21 Binocular Telescope snaps first image, 6:21 Black hole sets a record, 2:20 Black holes wind up galaxy arms, 9:19 Brightest starburst galaxy discovered, 12:23 C Calling all space probes, 10:64–10:65 Calling on Cassiopeia, 11:76 Canada to launch new asteroid hunter, 11:19 Canada’s handy robot, 1:24 Cannibal next door, The, 3:38 Capture images of our local star, 4:66–4:67 Cassini confirms Titan lakes, 12:27 Cassini scopes Saturn’s two-toned moon, 1:25 Cassini “tastes” Enceladus’ plumes, 7:26 Cepheus’ fall delights, 10:85 Choose the dome that’s right for you, 5:70–5:71 Clearing the air about seeing vs. -
Sulfur Hazes in Giant Exoplanet Atmospheres: Impacts on Reflected
Draft version February 28, 2017 Preprint typeset using LATEX style AASTeX6 v. 1.0 SULFUR HAZES IN GIANT EXOPLANET ATMOSPHERES: IMPACTS ON REFLECTED LIGHT SPECTRA Peter Gao1,2,3, Mark S. Marley, and Kevin Zahnle NASA Ames Research Center Moffett Field, CA 94035, USA Tyler D. Robinson4,5 Department of Astronomy and Astrophysics University of California Santa Cruz Santa Cruz, CA 95064, USA Nikole K. Lewis Space Telescope Science Institute Baltimore, MD 21218, USA 1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA 2NASA Postdoctoral Program Fellow [email protected] 4Sagan Fellow 5NASA Astrobiology Institute’s Virtual Planetary Laboratory ABSTRACT Recent work has shown that sulfur hazes may arise in the atmospheres of some giant exoplanets due to the photolysis of H2S. We investigate the impact such a haze would have on an exoplanet’s geometric albedo spectrum and how it may affect the direct imaging results of WFIRST, a planned NASA space telescope. For temperate (250 K < Teq < 700 K) Jupiter–mass planets, photochemical destruction of H2S results in the production of 1 ppmv of S8 between 100 and 0.1 mbar, which, if cool enough, ∼ will condense to form a haze. Nominal haze masses are found to drastically alter a planet’s geometric albedo spectrum: whereas a clear atmosphere is dark at wavelengths between 0.5 and 1 µm due to molecular absorption, the addition of a sulfur haze boosts the albedo there to 0.7 due to scattering. ∼ Strong absorption by the haze shortward of 0.4 µm results in albedos <0.1, in contrast to the high albedos produced by Rayleigh scattering in a clear atmosphere. -
The Impact of Giant Stellar Outflows on Molecular Clouds
The Impact of Giant Stellar Outflows on Molecular Clouds A thesis presented by H´ector G. Arce Nazario to The Department of Astronomy in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of Astronomy Harvard University Cambridge, Massachusetts October, 2001 c 2001, by H´ector G. Arce Nazario All Rights Reserved ABSTRACT Thesis Advisor: Alyssa A. Goodman Thesis by: H´ector G. Arce Nazario We use new millimeter wavelength observations to reveal the important effects that giant (parsec-scale) outflows from young stars have on their surroundings. We find that giant outflows have the potential to disrupt their host cloud, and/or drive turbulence there. In addition, our study confirms that episodicity and a time-varying ejection axis are common characteristics of giant outflows. We carried out our study by mapping, in great detail, the surrounding molecular gas and parent cloud of two giant Herbig-Haro (HH) flows; HH 300 and HH 315. Our study shows that these giant HH flows have been able to entrain large amounts of molecular gas, as the molecular outflows they have produced have masses of 4 to 7 M |which is approximately 5 to 10% of the total quiescent gas mass in their parent clouds. These outflows have injected substantial amounts of −1 momentum and kinetic energy on their parent cloud, in the order of 10 M km s and 1044 erg, respectively. We find that both molecular outflows have energies comparable to their parent clouds' turbulent and gravitationally binding energies. In addition, these outflows have been able to redistribute large amounts of their surrounding medium-density (n ∼ 103 cm−3) gas, thereby sculpting their parent cloud and affecting its density and velocity distribution at distances as large as 1 to 1.5 pc from the outflow source. -
Physical Processes in the Interstellar Medium
Physical Processes in the Interstellar Medium Ralf S. Klessen and Simon C. O. Glover Abstract Interstellar space is filled with a dilute mixture of charged particles, atoms, molecules and dust grains, called the interstellar medium (ISM). Understand- ing its physical properties and dynamical behavior is of pivotal importance to many areas of astronomy and astrophysics. Galaxy formation and evolu- tion, the formation of stars, cosmic nucleosynthesis, the origin of large com- plex, prebiotic molecules and the abundance, structure and growth of dust grains which constitute the fundamental building blocks of planets, all these processes are intimately coupled to the physics of the interstellar medium. However, despite its importance, its structure and evolution is still not fully understood. Observations reveal that the interstellar medium is highly tur- bulent, consists of different chemical phases, and is characterized by complex structure on all resolvable spatial and temporal scales. Our current numerical and theoretical models describe it as a strongly coupled system that is far from equilibrium and where the different components are intricately linked to- gether by complex feedback loops. Describing the interstellar medium is truly a multi-scale and multi-physics problem. In these lecture notes we introduce the microphysics necessary to better understand the interstellar medium. We review the relations between large-scale and small-scale dynamics, we con- sider turbulence as one of the key drivers of galactic evolution, and we review the physical processes that lead to the formation of dense molecular clouds and that govern stellar birth in their interior. Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Straße 2, 69120 Heidelberg, Germany e-mail: [email protected], [email protected] 1 Contents Physical Processes in the Interstellar Medium ...............