Planck Intermediate Results. XXVIII. Interstellar Gas and Dust in the Chamaeleon Clouds As Seen by Fermi LAT and Planck P
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Proper Motions of Young Stars in Chamaeleon II
A&A 556, A144 (2013) Astronomy DOI: 10.1051/0004-6361/201321217 & c ESO 2013 Astrophysics Proper motions of young stars in Chamaeleon II. New kinematical candidate members of Chamaeleon I and II Belén López Martí1, Francisco Jiménez-Esteban1,2,3, Amelia Bayo4,5, David Barrado1,6, Enrique Solano1,2, Hervé Bouy1, and Carlos Rodrigo1,2 1 Centro de Astrobiología (INTA-CSIC), Departamento de Astrofísica, PO Box 78, 28261 Villanueva de la Cañada, Madrid, Spain e-mail: [email protected] 2 Spanish Virtual Observatory, 2869 Madrid, Spain 3 Suffolk University, Madrid Campus, C/ Valle de la Viña 3, 28003 Madrid, Spain 4 European Southern Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile 5 Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany 6 Calar Alto Observatory, Centro Astronómico Hispano-Alemán, C/ Jesús Durbán Remón 2-2, 04004 Almería, Spain Received 1 February 2013 / Accepted 1 July 2013 ABSTRACT Context. The Chamaeleon star-forming region has been extensively studied in the last decades. However, most studies have been confined to the densest parts of the clouds. In a previous paper, we analysed the kinematical properties of the spectroscopically confirmed population of the Chamaeleon I and II clouds. Aims. We want to search for new kinematical candidate members to the Chamaeleon I and II moving groups, extending the studied area beyond the clouds, and to characterize these new populations using available information from public databases and catalogues. We also want to check if the populations of the moving groups are confined to the present dark clouds. Methods. Kinematic candidate members were initially selected on the basis of proper motions and colours using the Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4). -
Arxiv:0808.3207V1 [Astro-Ph] 23 Aug 2008 Nfgr .Nwonsaswr Rtdrcl Icvrdi C in Discovered Directly H first Were and Surroun Stars Variability Area Newborn the of 4
Handbook of Star Forming Regions Vol. II Astronomical Society of the Pacific, 2008 Bo Reipurth, ed. Chamaeleon Kevin L. Luhman Department of Astronomy and Astrophysics The Pennsylvania State University University Park, PA 16802, USA Abstract. The dark clouds in the constellation of Chamaeleon have distances of 160-180pc from the Sun and a total mass of ∼5000 M⊙. The three main clouds, Cha I, II, and III, have angular sizes of a few square degrees and maximum extinctions of AV ∼ 5-10. Most of the star formation in these clouds is occurring in Cha I, with the remainder in Cha II. The current census of Cha I contains 237 known members, 33 of which have spectral types indicative of brown dwarfs (>M6). Approximately 50 members of Cha II have been identified, including a few brown dwarfs. When interpreted with the evolutionary models of Chabrier and Baraffe, the H-R diagram for Cha I exhibits a median age of ∼2 Myr, making it coeval with IC 348 and slightly older than Taurus (∼1 Myr). TheIMF ofChaI reachesa maximumat a massof0.1-0.15 M⊙, and thus closely resembles the IMFs in IC 348 and the Orion Nebula Cluster. The disk fraction in Cha I is roughly constant at ∼ 50% from 0.01 to 0.3 M⊙ and increases to ∼ 65% at higher masses. In comparison, IC 348 has a similar disk fraction at low masses but a much lower disk fraction at M ∼> 1 M⊙, indicating that solar-type stars have longer disk lifetimes in Cha I. 1. Introduction The southern constellation of Chamaeleon contains one of the nearest groups of dark clouds to the Sun (d ∼ 160-180 pc). -
Andersson & Potter 2007
The Astrophysical Journal, 665:369Y389, 2007 August 10 A # 2007. The American Astronomical Society. All rights reserved. Printed in U.S.A. OBSERVATIONAL CONSTRAINTS ON INTERSTELLAR GRAIN ALIGNMENT B-G Andersson Center for Astrophysical Sciences, Johns Hopkins University, Baltimore, MD 21218; [email protected] and S. B. Potter South African Astronomical Observatory, Observatory 7935, Cape Town, South Africa; [email protected] Received 2006 September 21; accepted 2007 May 8 ABSTRACT We present new multicolor photopolarimetry of stars behind the Southern Coalsack. Analyzed together with multiband polarization data from the literature, probing the Chamaeleon I, Musca, Opiuchus, R CrA, and Taurus clouds, we show that the wavelength of maximum polarization (k max) is linearly correlated with the radiation en- vironment of the grains. Using far-infrared emission data, we show that the large scatter seen in previous studies of k max as a function of AV is primarily due to line-of-sight effects causing some AV measurements to not be a good tracer of the extinction (radiation field strength) seen by the grains being probed. The derived slopes in k max versus AV, for the individual clouds, are consistent with a common value, while the zero intercepts scale with the average values of the ratios of total to selective extinction (RV) for the individual clouds. Within each cloud we do not find direct correlations between k max and RV . The positive slope is consistent with recent developments in theory and indicating alignment driven by the radiation field. The present data cannot conclusively differentiate between direct radiative torques and alignment driven by H2 formation. -
Arxiv:2105.09338V2 [Astro-Ph.GA] 16 Jun 2021
Draft version June 18, 2021 Typeset using LATEX twocolumn style in AASTeX63 Stars with Photometrically Young Gaia Luminosities Around the Solar System (SPYGLASS) I: Mapping Young Stellar Structures and their Star Formation Histories Ronan Kerr,1 Aaron C. Rizzuto,1, ∗ Adam L. Kraus,1 and Stella S. R. Offner1 1Department of Astronomy, University of Texas at Austin 2515 Speedway, Stop C1400 Austin, Texas, USA 78712-1205 (Accepted May 16, 2021) ABSTRACT Young stellar associations hold a star formation record that can persist for millions of years, revealing the progression of star formation long after the dispersal of the natal cloud. To identify nearby young stellar populations that trace this progression, we have designed a comprehensive framework for the identification of young stars, and use it to identify ∼3×104 candidate young stars within a distance of 333 pc using Gaia DR2. Applying the HDBSCAN clustering algorithm to this sample, we identify 27 top-level groups, nearly half of which have little to no presence in previous literature. Ten of these groups have visible substructure, including notable young associations such as Orion, Perseus, Taurus, and Sco-Cen. We provide a complete subclustering analysis on all groups with substructure, using age estimates to reveal each region's star formation history. The patterns we reveal include an apparent star formation origin for Sco-Cen along a semicircular arc, as well as clear evidence for sequential star formation moving away from that arc with a propagation speed of ∼4 km s−1 (∼4 pc Myr−1). We also identify earlier bursts of star formation in Perseus and Taurus that predate current, kinematically identical active star-forming events, suggesting that the mechanisms that collect gas can spark multiple generations of star formation, punctuated by gas dispersal and cloud regrowth. -
Annual Report ESO Staff Papers 2018
ESO Staff Publications (2018) Peer-reviewed publications by ESO scientists The ESO Library maintains the ESO Telescope Bibliography (telbib) and is responsible for providing paper-based statistics. Publications in refereed journals based on ESO data (2018) can be retrieved through telbib: ESO data papers 2018. Access to the database for the years 1996 to present as well as an overview of publication statistics are available via http://telbib.eso.org and from the "Basic ESO Publication Statistics" document. Papers that use data from non-ESO telescopes or observations obtained with hosted telescopes are not included. The list below includes papers that are (co-)authored by ESO authors, with or without use of ESO data. It is ordered alphabetically by first ESO-affiliated author. Gravity Collaboration, Abuter, R., Amorim, A., Bauböck, M., Shajib, A.J., Treu, T. & Agnello, A., 2018, Improving time- Berger, J.P., Bonnet, H., Brandner, W., Clénet, Y., delay cosmography with spatially resolved kinematics, Coudé Du Foresto, V., de Zeeuw, P.T., et al. , 2018, MNRAS, 473, 210 [ADS] Detection of orbital motions near the last stable circular Treu, T., Agnello, A., Baumer, M.A., Birrer, S., Buckley-Geer, orbit of the massive black hole SgrA*, A&A, 618, L10 E.J., Courbin, F., Kim, Y.J., Lin, H., Marshall, P.J., Nord, [ADS] B., et al. , 2018, The STRong lensing Insights into the Gravity Collaboration, Abuter, R., Amorim, A., Anugu, N., Dark Energy Survey (STRIDES) 2016 follow-up Bauböck, M., Benisty, M., Berger, J.P., Blind, N., campaign - I. Overview and classification of candidates Bonnet, H., Brandner, W., et al. -
Proper Motions of Young Stars in Chamaeleon. II. New Kinematical
Astronomy & Astrophysics manuscript no. lopezmarti˙cham˙II c ESO 2021 May 28, 2021 Proper motions of young stars in Chamaeleon II. New kinematical candidate members of Chamaeleon I and II Belen´ Lopez´ Mart´ı1, Francisco Jimenez-Esteban´ 1;2;3, Amelia Bayo4;5, David Barrado1;6, Enrique Solano1;2, Herve´ Bouy1, and Carlos Rodrigo1;2 1 Centro de Astrobiolog´ıa (INTA-CSIC), Departamento de Astrof´ısica, P.O. Box 78, E-28261 Villanueva de la Canada,˜ Madrid, Spain e-mail: [email protected] 2 Spanish Virtual Observatory, Spain 3 Suffolk University, Madrid Campus, C/ Valle de la Vina˜ 3, E-28003 Madrid, Spain 4 European Southern Observatory, Alonso de Cordova´ 3107, Vitacura, Santiago, Chile 5 Max-Planck-Institut fur¨ Astronomie, Konigstuhl¨ 17, D-69117 Heidelberg, Germany 6 Calar Alto Observatory, Centro Astronomico´ Hispano-Aleman,´ C/ Jesus´ Durban´ Remon´ 2-2, E-04004 Almer´ıa, Spain Received; accepted ABSTRACT Context. The Chamaeleon star-forming region has been extensively studied in the last decades. However, most studies have been confined to the densest parts of the clouds. In a previous paper, we analysed the kinematical properties of the spectroscopically confirmed population of the Chamaeleon I and II clouds. Aims. We want to search for new kinematical candidate members to the Chamaeleon I and II moving groups, extending the studied area beyond the clouds, and to characterize these new populations using available information from public databases and catalogues. We also want to check if the populations of the moving groups are confined to the present dark clouds. Methods. Kinematic candidate members were initially selected on the basis of proper motions and colours using the Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4). -
August Meetings Comet NEOWISE C/2020 F3
July, 2020 August MeetingsJuly, 2020 The Milwaukee Astronomical Society is on the summer schedule. There will be no Membership Meetings in the summer months of June, July, and August. However, there will be a Board Meeting on August 10th, the second Monday of the month starting at 7PM. Due to the COVID-19 pandemic the meeting will be held through Zoom videocon- ference. The Board Meetings are open to the membership and everybody is welcome to attend who is interested in organizational and Observatory related issues. If you are not Inside this issue: a Board member but would like to attend please contact Tamas Kriska. The Astrophotography Focus Group will meet on Wednesday, August 12th at 7 PM August Meetings 1 trough Zoom videoconference. The specific topic of the meeting will be announced on the Google Group. Comet Neowise 1 The First Wednesday How to Meeting will also be held through Zoom videoconfer- st Minutes 2 ence on August 5 , from 7:30 PM. The MAS Google Group is as active as ever. Learn about the astronomical news, fol- Treasurer Report 2 low equipment related discussions, or just check out the latest images taken by fellow Observatory Direc- 2 Club members. tor Report Membership 2 Comet NEOWISE C/2020 F3 Comet NEOWISE 3 In the News 5 This month we had an Adopt a Scope 6 unexpected celestial visi- tor, the brightest comet Officers/Staff 6 in the northern hemi- Keyholders 6 sphere since Comet Hale –Bopp in 1997. The C/2020 F3, a long period comet with a near- parabolic orbit was dis- covered on March 27 during the NEOWISE mission of the Wide-field Infrared Survey Explorer (WISE) space telescope. -
Planck Intermediate Results. XXXII. the Relative Orientation Between the Magnetic Field and Structures Traced by Interstellar Dust DOI: 10.1051/0004-6361/201425044
The University of Manchester Research Planck intermediate results. XXXII. The relative orientation between the magnetic field and structures traced by interstellar dust DOI: 10.1051/0004-6361/201425044 Document Version Final published version Link to publication record in Manchester Research Explorer Citation for published version (APA): Adam, R., Ade, P. A. R., Aghanim, N., Alves, M. I. R., Arnaud, M., Arzoumanian, D., Ashdown, M., Aumont, J., Baccigalupi, C., Banday, A. J., Barreiro, R. B., Bartolo, N., Battaner, E., Benabed, K., Benoit-Lévy, A., Bernard, J. P., Bersanelli, M., Bielewicz, P., Bonaldi, A., ... Zonca, A. (2016). Planck intermediate results. XXXII. The relative orientation between the magnetic field and structures traced by interstellar dust. Astronomy and Astrophysics, 586, 1-25. https://doi.org/10.1051/0004-6361/201425044 Published in: Astronomy and Astrophysics Citing this paper Please note that where the full-text provided on Manchester Research Explorer is the Author Accepted Manuscript or Proof version this may differ from the final Published version. If citing, it is advised that you check and use the publisher's definitive version. General rights Copyright and moral rights for the publications made accessible in the Research Explorer are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Takedown policy If you believe that this document breaches copyright please refer to the University of Manchester’s Takedown Procedures [http://man.ac.uk/04Y6Bo] or contact [email protected] providing relevant details, so we can investigate your claim. -
Spitzer Approved Galactic Spitzer Approved Galactic
Printed_by_SSC Mar 25, 10 16:33Spitzer_Approved_Galactic Page 1/847 Mar 25, 10 16:33Spitzer_Approved_Galactic Page 2/847 Spitzer Space Telescope − Archive Research Proposal #20309 Spitzer Space Telescope − Archive Research Proposal #30144 PAH Emission Features in the 15 to 20 Micron Region: Emitting to the Beat of a Diamonds are a PAHs Best Friend Different Drummer Principal Investigator: Louis Allamandola Principal Investigator: Louis Allamandola Institution: NASA Ames Research Center Institution: NASA Ames Research Center Technical Contact: Louis Allamandola, NASA Ames Research Center Technical Contact: Louis Allamandola, NASA Ames Research Center Co−Investigators: Co−Investigators: Andrew Mattioda, SETI Andrew Mattioda, SETI Institute and NASA Ames Els Peeters, SETI Els Peeters, NASA Ames Research Center Douglas Hudgins, NASA Ames Research Center Douglas Hudgins, NASA Ames Research Center Alexander Tielens, NASA Ames Research Center Xander Tielens, Kapteyn Institute, The Netherlands Charles Bauschlicher, Jr., NASA Ames Research Center Charlie Bauschlicher, Jr., NASA Ames Research Center Science Category: ISM Science Category: ISM Dollars Approved: 56727.0 Dollars Approved: 72000.0 Abstract: Abstract: The mid−IR spectroscopic capabilities and unprecedented sensitivity of the Spitzer has added a new complex of bands near 17 um to the PAH emission band Spitzer Space Telescope has shown that the ubiquitious infrared (IR) emission family. This 17 um band complex, the second most intense of the PAH features, features can be used as probes of many galactic and extragalactic objects. carries unique information about the emitting species. Because these bands arise These features, formerly called the Unidentified Infrared (UIR) Bands, are now from drumhead vibrations of the hexagonal carbon skeleton, they carry generally attributed to the vibrational emission from polycyclic aromatic information directly related to PAH shape, size, and charge. -
The Brown Dwarf Population in the Chamaeleon I Cloud to Planets)
Astronomy & Astrophysics manuscript no. lopezmarti November 15, 2018 (DOI: will be inserted by hand later) The brown dwarf population in the Chamaeleon I cloud ⋆ B. L´opez Mart´ı12, J. Eisl¨offel2, A. Scholz2 and R. Mundt3 1 Observatori Astron`omic de la Universitat de Val`encia, Edifici d’Instituts d’Investigaci´o, Pol´ıgon La Coma, E- 46980 Paterna, Spain e-mail: [email protected] 2 Th¨uringer Landessternwarte, Sternwarte 5, D-07778 Tautenburg, Germany e-mail: [email protected], [email protected] 3 Max-Planck-Institut f¨ur Astronomie, K¨onigstuhl 17, D-69117 Heidelberg, Germany e-mail: [email protected] Received; accepted Abstract. We present the results of a multiband survey for brown dwarfs in the Chamaeleon I dark cloud with the Wide Field Imager (WFI) camera at the ESO/MPG 2.2-m telescope on La Silla (Chile). The survey has revealed a substantial population of brown dwarfs in this southern star forming region. Candidates were selected from R, I and Hα imaging observations. We also observed in two medium-band filters, M855 and M915, for the purpose of spectral type determination. The former filter covers a wavelength range containing spectral features characteristic of M-dwarfs, while the latter lies in a relatively featureless wavelength region for these late-type objects. A correlation was found between spectral type and (M855–M915) colour index for mid- to late M-type objects and early L-type dwarfs. With this method, we identify most of our object candidates as being of spectral type M5 or later. -
Annual Report Publications 2011
Publications Publications in refereed journals based on ESO data (2011) The ESO Library maintains the ESO Telescope Bibliography (telbib) and is responsible for providing paper-based statistics. Access to the database for the years 1996 to present as well as information on basic publication statistics are available through the public interface of telbib (http://telbib.eso.org) and from the “Basic ESO Publication Statistics” document (http://www.eso.org/sci/libraries/edocs/ESO/ESOstats.pdf), respectively. In the list below, only those papers are included that are based on data from ESO facilities for which observing time is evaluated by the Observing Programmes Committee (OPC). Publications that use data from non-ESO telescopes or observations obtained during ‘private’ observing time are not listed here. Absil, O., Le Bouquin, J.-B., Berger, J.-P., Lagrange, A.-M., Chauvin, G., Alecian, E., Kochukhov, O., Neiner, C., Wade, G.A., de Batz, B., Lazareff, B., Zins, G., Haguenauer, P., Jocou, L., Kern, P., Millan- Henrichs, H., Grunhut, J.H., Bouret, J.-C., Briquet, M., Gagne, M., Gabet, R., Rochat, S., Traub, W., 2011, Searching for faint Naze, Y., Oksala, M.E., Rivinius, T., Townsend, R.H.D., Walborn, companions with VLTI/PIONIER. I. Method and first results, A&A, N.R., Weiss, W., Mimes Collaboration, M.C., 2011, First HARPSpol 535, 68 discoveries of magnetic fields in massive stars, A&A, 536, L6 Adami, C., Mazure, A., Pierre, M., Sprimont, P.G., Libbrecht, C., Allen, D.M. & Porto de Mello, G.F. 2011, Mn, Cu, and Zn abundances in Pacaud, F., -
The Brown Dwarf Population in the Chamaeleon I Cloud
A&A 416, 555–576 (2004) Astronomy DOI: 10.1051/0004-6361:20031720 & c ESO 2004 Astrophysics The brown dwarf population in the Chamaeleon I cloud B. L´opez Mart´ı1,2,J.Eisl¨offel2, A. Scholz2, and R. Mundt3 1 Observatori Astron`omic de la Universitat de Val`encia, Edifici d’Instituts d’Investigaci´o, Pol´ıgon La Coma, 46980 Paterna, Spain 2 Th¨uringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany e-mail: [email protected]; [email protected] 3 Max-Planck-Institut f¨ur Astronomie, K¨onigstuhl 17, 69117 Heidelberg, Germany e-mail: [email protected] Received 16 April 2003 / Accepted 19 November 2003 Abstract. We present the results of a multiband survey for brown dwarfs in the Chamaeleon I dark cloud with the Wide Field Imager (WFI) camera at the ESO/MPG 2.2-m telescope on La Silla (Chile). The survey has revealed a substantial population of brown dwarfs in this southern star-forming region. Candidates were selected from R, I and Hα imaging observations. We also observed in two medium-band filters, M 855 and M 915, for spectral type determination. The former filter covers a wavelength range containing spectral features characteristic of M-dwarfs, while the latter lies in a relatively featureless wavelength region for these late-type objects. A correlation was found between spectral type and (M 855–M 915) colour index for mid- to late M-type objects and early L-type dwarfs. With this method, we identify most of our object candidates as being of spectral type M 5 or later.