DOCSLIB.ORG

1. Introduction 2. Observations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
1. Introduction 2. Observations THE ASTROPHYSICAL JOURNAL, 498:278È292, 1998 May 1 ( 1998. The American Astronomical Society. All rights reserved. Printed in U.S.A. STELLAR CONTENT OF THE GALACTIC STARBURST TEMPLATE NGC 3603 FROM ADAPTIVE OPTICS OBSERVATIONS1 F.EISENHAUER,2 A.QUIRRENBACH,2 H. ZINNECKER,3 AND R. GENZEL2 Received 1997 October 1; accepted 1997 December 12 ABSTRACT We present near-infrared adaptive optics imaging of the Galactic starburst template NGC 3603 and its stellar center HD 97950. There is clear evidence for the presence of stars down to 1M_ or less. No cuto† or turnover in the initial mass function is evident. Applying theoretical models of the preÈmain- sequence evolution of intermediate-mass stars to the observed color-color diagram, the color-magnitude diagram, and the luminosity function, we constrain both the age distribution and the initial mass func- tion. Within the systematic errors, this initial mass function follows a Salpeter power law with index ! ¹ [0.73 down to the observational limit of less than 1M_. The stars with less than 4M_ appear to be younger than 106 yr, in contrast to previous age determinations of the high-mass content of HD 97950. Subject headings: Hertzsprung-Russell diagram È H II regions È ISM: individual (NGC 3603) È stars: formation È stars: luminosity function, mass function 1. INTRODUCTION low-mass stars(Zinnecker, McCaughrean, & Wilking 1993), even down to preÈmain-sequence (PMS) objects near the Apart from W49, the H II region NGC 3603 is the most hydrogen burning limit(Hillenbrand 1997). On the other massive giant H II region in our Galaxy(Goss & Radhak- hand, the jury is still out on the R136 cluster in the 30 rishnan1969). It is located in the Carina spiral arm at a Doradus H II region, which is an order of magnitude more distance of 7.2 kpc (1A + 0.035 pc). A cluster of about 50 O luminous than the NGC 3603 cluster. Knowing the PMS stars dominated by the Trapezium-like system HD 97950 low-mass population in the Orion Nebula cluster, NGC provides the ionizing radiation (Clayton 1986; Melnick, 3603, and R136, with roughly one, 10, and 100 massive O Tapia, & Terlevich1989; Mo†at 1983). The age of the NGC stars, respectively, will go a long way to helping us under- 3603 cluster has been estimated to be 2È3 Myr(Melnick et stand whether the presence of an increasing number of al.1989). With three Wolf-Rayet (W-R) star candidates and massive stars somehow quenches the formation of low-mass six O3 stars in a volume less than a cubic light-year (Drissen stars. If so, and only if this is so, the concept of bimodal star et al.1995), the central core of NGC 3603 is the densest formation(Gu sten & Mezger 1982; Larson 1986) has a system of high-mass stars known in the Galaxy. Its total quantitative basis beyond speculation. bolometric luminosity is on the order of 107 L _. NGC 3603 thus can be considered as a template for a massive cluster of 2. OBSERVATIONS young stars typical for the building blocks of starbursts in external galaxies. Although its population of high-mass All observations were carried out with the European stars is fairly well known from Hubble Space Telescope Southern Observatory (ESO) adaptive optics (AO) system (HST ) imaging(Mo†at, Drissen, & Shara 1994) and ADONIS at the 3.6 m telescope at La Silla, Chile, and the speckle-masking observations(Hofmann, Seggewiss, & dedicated near-infrared camera SHARP II(R. Hofmann et Weigelt1995), not much is yet known about intermediate- al.1995), developed at the Max-Planck-Institut fu r extra- and low-mass stars. terrestrische Physik, Germany. ADONIS provides a real- Since it is the closest analog in the Galaxy to a starburst, time correction of the atmospheric wave-front distortions, however, its low-mass stellar content is also of considerable and, in the best cases, the di†raction from the telescope interest. This is because there is observational (e.g., Rieke et limits the spatial resolution. As with every AO system, al.1980, 1993) and theoretical (e.g., Silk 1995) evidence that however, the Ðnal image quality depends on the brightness massive star formation regions in starburst systems are deÐ- of the reference star and its distance from the object of cient in low-mass stars (M ¹ 3M_). It is the purpose of interest. We selected the B1.5 supergiant Sher 25 (Brandner this investigation to use deep star counts as a means of et al.1997a, 1997b) as the wave-front reference star, separat- testing this claim. Even though NGC 3603 is only a small ed by about 20A from the stellar center HD 97950 of NGC starburst by extragalactic standards(Kennicutt 1984), it is a 3603. Its visual magnitude of V \ 12.2(Melnick et al. 1989) major stepping stone for establishing whether starburst is just sufficient for a satisfactory image improvement by initial mass functions (IMFs) are truncated or not. ADONIS(V B 13). The camera SHARP II is based on a It is worth mentioning that the Orion Nebula cluster 256 pixel ] Limit256 pixel NICMOS III detector. The observed (L B 105 L _, two O stars) is certainly not deÐcient in wavelength range covers the atmospheric bands J (1.11È bol 1.40 km), H (1.47È1.82 km), and K (1.99È2.32 km). Com- 1 Based on observations collected at the European Southern Observa- pared with the Johnson K band, we used a somewhat tory, La Silla, Chile, ESO 54.E-1000, ESO 56.D-0573, ESO 57.D-0354. narrower Ðlter to suppress as much as possible the thermal 2 Max-Planck-Institut fu r extraterrestrische Physik, Giessenbach- background. The reference stars SA 100-280 and SA 106- strasse, 85740 Garching, Germany; eisenhau=mpe-garching.mpg.de, genzel=mpe-garching.mpg.de, qui=mpa-garching.mpg.de. 1024 provided the photometric calibration. 3 Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 While we observed the T-shaped mosaic(Fig. 1 [Pl. Potsdam, Germany; hzinnecker=aip.de. 3]) of NGC 3603 with a pixel scale of 100 mas pixel~1, the 278 STELLAR CONTENT OF NGC 3603 279 central region(Fig. 2) of 12A.8]12A.8 was also imaged with could not achieve the same AO correction for the mosaic. In a pixel scale of 50 mas pixel~1. The wave-front reference addition, the coarse sampling with pixels equivalent to 100 star Sher 25 can easily be found in the center of the mosaic; mas increased the FWHM. Depending on the distance to the stellar center of NGC 3603 lies about 20A to the south. the wave-front reference star, the FWHM is between 0A.23 The imaged area is 2190 arcsec2. In the detailed images of and0A.33 in the K band, 0A.32 and 0A.42 in the H band, and the stellar center, the total integration time amounts to 8400 0A.31and 0A.39 in the J band. sintheKband, 9000 s in the H band, and 1500 s in the J As we will explain in° 3, the conservative detection limit band. The mosaic was built from eight di†erent Ðelds with for a point source is about 19.3 (18.4) in K, 19.3 (18.9) in H, integration times of 2400 s (K), 1860 s (H), and 1560 s (J) for and 19.2 (18.4) in J (the numbers enclosed in parentheses the three central Ðelds and integration times of 800 s (K), refer to the detailed images of the central region). 620s(H), and 520 s (J) for the Ðve Ðelds north of Sher 25. DATA REDUCTION Each Ðeld itself is composed of multiple frames with inte- 3. gration times between 1 and 5 s. We could not increase this First we subtracted the sky background from the individ- integration time, because the brightest stars (about 8th ual images, applied a Ñat Ðeld to correct for the variation in magnitude in K band) saturated the detector already within the sensitivity across the Ðeld of view, and corrected for about 3 s. dead pixels. In the mosaic we reconstructed the background Since the reference star was simply too faint and too of every single pixel from its minimal intensity in the eight distant from HD 97950, the AO could not provide fully di†erent Ðelds. In the case of the detailed observations in di†raction-limited images. The applied correction reduced the very center of NGC 3603, we observed separate sky the FWHM of a point source in the detailed images to 0A.18 Ðelds. The Ñat Ðeld comes from sky frames recorded during in the K band,0A.30 in the H band, and 0A.31 in the J band. sunrise and sunset. The large variation in the intensities of These numbers and all of the numbers below refer to the the individual frames allows an accurate determination of stacked images containing all the individual frames of short the Ñat Ðeld in the presence of thermal background and integration times. Close to the reference star, the image straylight. A linear interpolation was used to correct the quality was somewhat better; the FWHM was0A.16 (K), dead and noisy pixels. 0A.27(H), and 0A.26 (J). Unfortunately, the seeing on La Silla Owing to mechanical bending and slightly di†erent Ðeld was not monitored systematically during the observations; positions in the various observations, we had to register the we estimate that the atmospheric seeing was about 1A not individual images before co-adding them. We determined including the turbulence within the dome and the telescope the direction and absolute value of the displacement for itself.
Load more

Recommended publications
  • Two O2ifwn6 Stars Possibly Ejected from the Massive Young Galactic
    Mon. Not. R. Astron. Soc. 416, 501–508 (2011) doi:10.1111/j.1365-2966.2011.19062.x Two O2 If*/WN6 stars possibly ejected from the massive young Galactic cluster Westerlund 2 , A. Roman-Lopes,1 R. H. Barba1 2 and N. I. Morrell3 1Department of Physics, Universidad de La Serena, Benavente 980, La Serena, Chile 2Instituto de Ciencias Astronomicas, de la Tierra, y del Espacio (ICATE-CONICET), Av. Espana˜ 1512 Sur, J54202DSP San Juan, Argentina 3Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena, Chile Accepted 2011 May 12. Received 2011 May 10; in original form 2010 September 23 ABSTRACT In this paper we report the identification of two new Galactic O2 If*/WN6 stars (WR20aa and WR20c), on the outskirts of the massive young stellar cluster Westerlund 2. The morphological similarity between the near-infrared spectra of the new stars with that of WR20a and WR21a (two of the most massive binaries known to date) is remarkable, indicating that probably they are also very massive stars. New optical spectroscopic observations of WR20aa suggest an intermediate O2 If*/WN6 spectral type. Based on a mosaic made from the 3.6 µm Spitzer IRAC images of the region including part of the RCW49 complex, we studied the spatial location of the new emission line stars, finding that WR20aa and WR20c are well displaced from the centre of Westerlund 2, being placed at ≈36 pc (15.7 arcmin) and ≈58 pc (25.0 arcmin), respectively, for an assumed heliocentric distance of 8 kpc. Also, very remarkably, a radius vector connecting the two stars would intercept the Westerlund 2 cluster exactly at the place where its stellar density reaches a maximum.
    [Show full text]
  • Publications of the Astronomical Society of the Pacific 108: 8-34, 1996 January
    Publications of the Astronomical Society of the Pacific 108: 8-34, 1996 January Invited Review Paper Astrophysics in 1995 Virginia Trimble Department of Astronomy, University of Maryland, College Park, Maryland 20742-2421 and Department of Physics, University of California, Irvine, California 92717-4575 Peter J. T. Leonard Department of Astronomy, University of Maryland, College Park, Maryland 20742-2421 Received 1995 October 26; accepted 1995 October 27 ABSTRACT. Ap95 differs from Ap91 to Ap94 primarily in Ap number. That is, it once again attempts to highlight some areas of our mutual science where a major event has occurred during the year (a possible solution of the Type II supernova problem, the faintness of quasar host galaxies, the collision of Shoemaker-Levy 9 with Jupiter), but also to focus on some topics where dogged determination is producing more gradual advances (dense star clusters, the second-parameter problem, inventories of nearby objects, and dark-matter candidates). In moderate departure from the rules of Ap92-94, there has been some deliberate up-dating of topics discussed previously. The topics are only partly ordered from nearby to far away. 1. INTRODUCTION Journal. Another, less publicized, change of editors has "For crying out loud," we can hear you saying, "is it modified the journal so much that Vinod Krishan's Bulletin them again!" Well, yes. This is the fifth annual mustering of of the Astronomical Society of India (BASI in the references) the sheep and goats of astronomical/astrophysical research, has been added to the list of journals to be scanned regularly. based on journals that reached library shelves between 1 Oc- Last year, we worried a bit about paying too much atten- tober 1994 and 30 September 1995.
    [Show full text]
  • The Massive Star Content of NGC 36031
    Accepted by the Astronomical Journal The Massive Star Content of NGC 36031 Nicholas W. Melena2, Philip Massey2, Nidia I. Morrell3, Amanda M. Zangari2,4 ABSTRACT We investigate the massive star content of NGC 3603, the closest known giant H II region. We have obtained spectra of 26 stars in the central cluster using the Baade 6.5-m telescope (Magellan I). Of these 26 stars, 16 had no previous spectroscopy. We also obtained photometry of all of the stars with previous or new spectroscopy, primarily using archival HST ACS/HRC images. The total number of stars that have been spectroscopically classified in NGC 3603 now stands at 38. The sample is dominated by very early O type stars (O3); there are also several (previously identified) H-rich WN+abs stars. We derive E(B − V )=1.39, and find that there is very little variation in reddening across the cluster core, in agreement with previous studies. Our spectroscopic parallax is consistent with the kinematic distance only if the ratio of total to selective extinction is anomalously high within the cluster, as argued by Pandey et al. Adopting their reddening, we derive a distance of 7.6 kpc. We discuss the various distance estimates to the cluster, and note that although there has been a wide range of values in the recent literature (6.3-10.1 kpc) there is actually good agreement with the apparent distance modulus of the cluster—the disagreement has been the result of the uncertain reddening correction. We construct our H-R diagram using the apparent distance modulus with a correction for the slight difference in differential reddening from star to star.
    [Show full text]
  • General Disclaimer One Or More of the Following Statements May Affect This Document
    General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) I OASA-CF-1692510) WOLF-RAY? 7 FWWMI^NA N82-33294 (Joint inst. for Lab. kstroph y sics) 34 p HC A03/MF V1 CSCL M3A Unclas G3/85 33535 WOLF-RAYET PHENOMENA * P. S. Conti Joint Institute for Laboratory Astrophysics, University of Colorado and National Bureau of Standards, and Department of Astrophysical, Planetary and Atmospheric Sciences, University of Colorado, Boulder, CO 80309 I. INTRODUMON I have been aske^. to review in broad terms the concept of Wolf- Rayet (W-R) phenomena, that is, to outline what we currently know about the properties of stars showing such phenomena and to indicate the directions in which future work is leading. I thought I would 6egin by listing the characteristics of W-R spectra to which probably all the participants at this Symposium will be able to agree.
    [Show full text]
  • Winds of Massive Stars: High Resolution X-Ray Spectra of Stars in NGC 3603
    DRAFT VERSION NOVEMBER 27, 2018 Typeset using LATEX preprint style in AASTeX62 Winds of Massive Stars: High Resolution X-ray Spectra of Stars in NGC 3603 DAVID P. HUENEMOERDER,1 NORBERT S. SCHULZ,1 AND JOY S. NICHOLS2 1Massachusetts Institute of Technology 77 Massachusetts Ave. Cambridge, MA 02139, USA 2Harvard-Smithsonian Center for Astrophysics 60 Garden St. Cambridge, MA 02138, USA ABSTRACT The cluster NGC 3603 hosts some of the most massive stars in the Galaxy. With a mod- est 50 ks exposure with the Chandra High Energy Grating Spectrometer, we have resolved emission lines in spectra of several of the brightest cluster members which are of WNh and O spectral types. This observation provides our first definitive high-resolution spectra of such stars in this nearby starburst region. The stars studied have broadened X-ray emission lines, some with blue-shifted centroids, and are characteristic of massive stellar winds with terminal velocities around 2000–3000 km s−1. X-ray luminosities and plasma temperatures are very high for both the WNh and O stars studied. We conclude that their X-rays are likely the result of colliding winds. Keywords: stars: Wolf-Rayet — stars: massive — stars: individual (HD 97950, MTT 68, MTT 71, Sher 47) — X-rays: stars 1. INTRODUCTION The starburst phenomenon is an influential process in the evolution of stellar systems. The formation of massive stars can have a profound effect on their environment through ionizing radiation, kinetic energy of massive winds, and ultimately supernovae explosions. NGC 3603 is a relatively nearby galactic starburst region, close enough that individual stars can be observed in detail.
    [Show full text]
  • Infrared Observations of NGC 3603
    A&A 400, 223–239 (2003) Astronomy DOI: 10.1051/0004-6361:20021894 & c ESO 2003 Astrophysics Infrared observations of NGC 3603 II. A 11.9 µmand18µmsurvey D. E. A. N¨urnberger1,2 and T. Stanke3 1 European Southern Observatory, Casilla 19001, Santiago 19, Chile 2 Institut f¨ur Theoretische Physik und Astrophysik, Univ. W¨urzburg, Am Hubland, 97074 W¨urzburg, Germany 3 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, 53121 Bonn, Germany Received 2 July 2002 / Accepted 23 December 2002 Abstract. We present results of the first sub-arcsec resolution mid infrared survey of the southern hemisphere giant H re- gion NGC 3603. We have observed selected fields in the vicinity of the OB cluster at wavelengths of 11.9 µm and 18 µmusing TIMMI 2 mounted on the ESO 3.6 m telescope. These fields comprise areas with dense molecular cores, embedded near infrared sources as well as several OH, H2OandCH3OH maser sources, which give indications of ongoing star formation processes. We report the detection of 36 mid infrared point sources and additionally provide flux measurements for 42 knots of diffuse emission. In the area surveyed the protostar IRS 9A is found to be the most luminous source at both 11.9 µm and 18 µm. Located in its immediate vicinity two more sources (IRS 9B and IRS 9C) also exhibit significant 11.9 µm and 18 µm emission, thus providing further indications for IRS 9 being an association of protostars in its own right. Several other 11.9 µm point sources are related to near infrared sources with strong K-band excess emission and/or to maser sources, which classifies them as young sources, too.
    [Show full text]
  • The Luminous Stellar Content of 30 Doradus and Ngc 3603 - the Nearest Visible Giant Hii Regions
    THE LUMINOUS STELLAR CONTENT OF 30 DORADUS AND NGC 3603 - THE NEAREST VISIBLE GIANT HII REGIONS A.F.J. Moffat Dept. de physique, Univ. de Montréal, Canada M.M. Shara Space Telescope Science Inst., Baltimore, U.S.A. W. Seggewiss Univ.-Sternwarte Bonn, F.R. Germany 30 Dor in the LMC and NGC 3603 in the Galaxy are the nearest visible examples of similar giant (or even more massive supergiant) HII regions being studied in other more distant galaxies, where spatial resolution is a much more serious problem. Hence, understanding 30 Dor and NGC 3603 may provide important clues to understanding extragalactic giant HII regions in general. On an angular scale, the bright stellar core regions of 30 Dor and NGC 3603 are very similar. On the basis of CCD imagery, Fig.l shows that the central radial light distribution of each region satisfies a semi-empirical King profile for spherically symmetric, isothermal stellar sys­ tems, over a span of two orders of magnitude in radius. Allowing for background starlight (nebular light is almost negligible), the partially resolved, luminous central objects RI36 (which emits ^ 20% of the total starlight in 30 Dor) and HD 97950, respectively, do not contain stars that are significantly brighter than adjacent, isolated stars of high but normal luminosity (and mass), i.e. we find no evidence for supermassive stars. Wolf-Rayet stars were detected using CCD image subtraction (narrow band minus broad band filter centered on the intense 4650-4686 A emission feature). We confirm that the number ratio of WR to 0 stars in 30 Dor and NGC 3603 is normal (^ 0.05) compared to other less exotic regions.
    [Show full text]
  • Multiplicity of Massive Stars
    Multiplicity of massive stars Hans Zinnecker Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany, [email protected] Summary. We review the multiplicity of massive stars by compiling the abstracts of the most relevant papers in the field. We start by discussing the massive stars in the Orion Trapezium Cluster and in other Galactic young clusters and OB associa- tions, and end with the R136 cluster in the LMC. The multiplicity of field O-stars and runaway OB stars is also reviewed. The results of both visual and spectroscopic surveys are presented, as well as data for eclipsing systems. Among the latter, we find the most massive known binary system WR20a, with two ∼ 80 M components in a 3 day orbit. Some 80 % of the wide visual binaries in stellar associations are in fact hierarchical triple systems, where typically the more massive of the binary components is itself a spectroscopic or even eclipsing binary pair. The multiplicity (number of companions) of massive star primaries is significantly higher than for low-mass solar-type primaries or for young low-mass T Tauri stars. There is also a striking preponderance of very close nearly equal mass binary systems (the origin of which has recently been explained in an accretion scenario). Finally, we offer a new idea as to the origin of massive Trapezium systems, frequently found in the centers of dense young clusters. 1 The origin of the Orion Trapezium system Let us begin by discussing the origin of the massive stars in the center of the Orion Nebula Cluster, i.e.
    [Show full text]
  • SCYON Issue 66
    edited by Giovanni Carraro, Martin Netopil, and Ernst Paunzen http://www.univie.ac.at/scyon/ email: [email protected] The official Newsletter of the IAU Commission H4. SCYON Issue No. 66 November 25th, 2015 Dear colleagues, With this issue we would like to draw your attention on the recent contribution of the old Com- mission 37 to the special issue of the IAU Transaction A, called Legacy volume, announced by Thierry Montmerle, IAU secretary for the term 2012{15. The motivation for this was to provide the astronom- ical community with a special volume that reflects the significant changes the IAU underwent very recently. This contribution has been edited by the organising committee of Commission 37, and prepared by leading scientists members of the star cluster commission (now called H4). It summarises the main results of research in our field in the last decade. Ignacio Negueruela presented highlights on massive star clusters and star forming regions in the Milky Way, while Elena Glushkova summarised results obtained for Galactic open clusters. Eugenio Carretta and Angela Bragaglia write on globular clusters and photometric and spectroscopic signatures of multiple populations. Finally, Tom Richtler reports about extra-galactic star clusters. We recently posted it at <http://arxiv.org/abs/1511.00835>. We expect this contribution to be an inspiring reference for the star cluster community. Please help us to disseminate it! CONTENTS About the Newsletter Abstracts of refereed papers . 1 SCYON publishes abstracts from any Star Forming Regions ..................2 area in astronomy, which are relevant to Galactic Open Clusters .................3 research on star clusters.
    [Show full text]
  • Bibliography from ADS File: Weigelt.Bib August 16, 2021 1
    Bibliography from ADS file: weigelt.bib Madura, T., Gull, T. R., Clementel, N., et al., “3D time-dependent hydrody- August 16, 2021 namical and radiative transfer modeling of Eta Carinae’s innermost fossil colliding wind structures”, 2019IAUS..346...62M ADS Chen, L., Moór, A., Kreplin, A., et al., “Variable Warm Dust around the Herbig Kokoulina, E., Matter, A., López, B., et al., “First MATISSE L-band observa- Ae Star HD 169142: Birth of a Ring?”, 2019ApJ...887L..32C ADS tions of HD 179218. Is the inner 10 au region rich in carbon dust particles?”, Matter, A., Labadie, L., Kreplin, A., et al., “Evidence of a discontinu- 2021A&A...652A..61K ADS ous disk structure around the Herbig Ae star HD 139614 (Corrigendum)”, Damineli, A., Navarete, F., Hillier, D. J., et al., “Spectroscopic signatures of the 2019A&A...632C...2M ADS vanishing natural coronagraph of Eta Carinae”, 2021MNRAS.505..963D Mehner, A., de Wit, W. J., Asmus, D., et al., “Mid-infrared evolution of η Cari- ADS nae from 1968 to 2018”, 2019A&A...630L...6M ADS Thomas, J. D., Richardson, N. D., Eldridge, J. J., et al., “The or- Monnier, J., Aarnio, A., Absil, O., et al., “A Realistic Roadmap to Formation bit and stellar masses of the archetype colliding-wind binary WR 140”, Flying Space Interferometry”, 2019BAAS...51g.153M ADS 2021MNRAS.504.5221T ADS Monnier, J., Aarnio, A., Absil, O., et al., “Setting the Stage for the Planet For- 2019BAAS...51g.133M Hocdé, V., Nardetto, N., Matter, A., et al., “Mid-infrared circumstellar emis- mation Imager”, ADS Ohnaka, K., Weigelt, G., & Hofmann, K.-H., “Infrared Interferometric Three- sion of the long-period Cepheid ` Carinae resolved with VLTI/MATISSE”, dimensional Diagnosis of the Atmospheric Dynamics of the AGB Star R Dor 2021A&A...651A..92H ADS with VLTI/AMBER”, 2019ApJ...883...89O ADS Kokoulina, E., Matter, A., López, B., et al., “First MATISSE L-band observa- Corcoran, M.
    [Show full text]
  • The Full Appendices with All References
    Breakthrough Listen Exotica Catalog References 1 APPENDIX A. THE PROTOTYPE SAMPLE A.1. Minor bodies We classify Solar System minor bodies according to both orbital family and composition, with a small number of additional subtypes. Minor bodies of specific compositions might be selected by ETIs for mining (c.f., Papagiannis 1978). From a SETI perspective, orbital families might be targeted by ETI probes to provide a unique vantage point over bodies like the Earth, or because they are dynamically stable for long periods of time and could accumulate a large number of artifacts (e.g., Benford 2019). There is a large overlap in some cases between spectral and orbital groups (as in DeMeo & Carry 2014), as with the E-belt and E-type asteroids, for which we use the same Prototype. For asteroids, our spectral-type system is largely taken from Tholen(1984) (see also Tedesco et al. 1989). We selected those types considered the most significant by Tholen(1984), adding those unique to one or a few members. Some intermediate classes that blend into larger \complexes" in the more recent Bus & Binzel(2002) taxonomy were omitted. In choosing the Prototypes, we were guided by the classifications of Tholen(1984), Tedesco et al.(1989), and Bus & Binzel(2002). The comet orbital classifications were informed by Levison(1996). \Distant minor bodies", adapting the \distant objects" term used by the Minor Planet Center,1 refer to outer Solar System bodies beyond the Jupiter Trojans that are not comets. The spectral type system is that of Barucci et al. (2005) and Fulchignoni et al.(2008), with the latter guiding our Prototype selection.
    [Show full text]
  • The Origin of Very Massive Stars Around NGC 3603
    LJMU Research Online Kalari, VM, Vink, JS, de Wit, WJ, Bastian, N and Mendez, RA The origin of very massive stars around NGC 3603 http://researchonline.ljmu.ac.uk/id/eprint/10921/ Article Citation (please note it is advisable to refer to the publisher’s version if you intend to cite from this work) Kalari, VM, Vink, JS, de Wit, WJ, Bastian, N and Mendez, RA (2019) The origin of very massive stars around NGC 3603. ASTRONOMY & ASTROPHYSICS, 625. ISSN 1432-0746 LJMU has developed LJMU Research Online for users to access the research output of the University more effectively. Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Users may download and/or print one copy of any article(s) in LJMU Research Online to facilitate their private study or for non-commercial research. You may not engage in further distribution of the material or use it for any profit-making activities or any commercial gain. The version presented here may differ from the published version or from the version of the record. Please see the repository URL above for details on accessing the published version and note that access may require a subscription. For more information please contact [email protected] http://researchonline.ljmu.ac.uk/ A&A 625, L2 (2019) Astronomy https://doi.org/10.1051/0004-6361/201935107 & c ESO 2019 Astrophysics LETTER TO THE EDITOR The origin of very massive stars around NGC 3603 V. M. Kalari1,2, J. S. Vink3, W.
    [Show full text]