High resolution spectroscopy of the BCD galaxy Haro 15:I. Internal kinematics

Using echelle spectroscopy, obtained at Las Campanas Observatory, we present a detailed study of the internal kinematics of the nebular material in multiple knots of the blue compact dwarf galaxy Haro 15. A detailed analysis of the complex emission line profiles show the presence of an underlying broad component in almost all knots, and the brightest star-forming region shows unmistakable signs for the presence of two distinct narrow kinematical components. We also study the information that our analysis provides regarding the motion of the individual knots in the Haro 15 galaxy potential, confirming that they follow galactic rotation. Finally, we examine the relation between their velocity dispersion and luminosity, finding that almost all knots follow the relation for virialised systems. This holds for the strong narrow components identified in complex fits and for single profile fits, although the latter show a flatter slope. In agreement with previous findings, in this paper we show that the existence of multiple kinematical components among massive starbursts cannot be overlooked, as it has a noticeable effect on any subsequent analysis that relies on basic parameters.Comment: 12 pages, 21 figure

New giant H II regions in the southern sky

We present results of a search for giant H II regions in southern galaxies. Using high-resolution spectra, obtained with the Magellan Inamori Kyocera Echelle (MIKE) at the Las Campanas Magellan II telescope, we were able to resolve the emission-line profiles and determine the intrinsic velocity dispersion of the ionized gas. Out of four observed regions, selected from previous CCD narrow-band photometry, we detected three H II regions showing supersonic velocity dispersion, characteristic of giant H II regions, and their location in diagnostic diagrams suggests that a powerful starburst is the source of ionization energy.Facultad de Ciencias Astronómicas y Geofísica

Giant H II regions in NGC 7479 and NGC 6070

We present new results from our search for giant H II regions in galaxies visible from the Southern hemisphere. In this work we study two galaxies: NGC 7479 and NGC 6070. Using high-resolution spectra, obtained with different instruments at Las Campanas Observatory, we are able to resolve the emission-line profile widths and determine the intrinsic velocity dispersion of the ionized gas. We detect profile widths corresponding to supersonic velocity dispersions in the six observed H II regions. We find that all of them show at least two distinct kinematical components: a relatively narrow feature (between 11 and 22 km s-1) and a broader (between 31 and 77 km s-1) component. Two of the regions show a complex narrow profile in all ion lines, which can be further split into two components with different radial velocities. Whereas the wing broadening of the overall profile can be fitted with a low-intensity broad component for almost all profiles, in one region it was better reproduced by two separate shell-like wings. We have analysed the impact that the presence of multiple components has on the location of the H II regions in the log (L)-log (σ) plane. Although the overall distribution confirms the presence of a regression, the precise location of the regions in the plane is strongly dependent on the components derived from the profile fitting.Facultad de Ciencias Astronómicas y Geofísica

High-resolution spectroscopy of the blue compact dwarf galaxy Haro 15 – I. Internal kinematics

This is an electronic version of an article published in Monthly Notices of the Royal Astronomical Society. Firpo, V., Bosch, G., Hägele, G.F., Díaz, A.I. and N. Morrell. High-resolution spectroscopy of the blue compact dwarf galaxy Haro 15 –I. Internal kinematics. Monthly Notices of the Royal Astronomical Society 414 (2011): 3288-329

Star forming regions linked to RCW 78 and the discovery of a new IR bubble

Aims. With the aim of investigating the presence of molecular and dust clumps linked to two star forming regions identified in the expanding molecular envelope of the stellar wind bubble RCW 78, we analyzed the distribution of the molecular gas and cold dust. Methods. To accomplish this study we performed dust continuum observations at 870 μm and 13CO(2-1) line observations with the Atacama Pathfinder EXperiment (APEX) telescope, using the Large Apex BOlometer CAmera (LABOCA) and SHeFI-1 instruments, respectively, and analyzed Herschel images at 70, 160, 250, 350, and 500 μm. Results. These observations allowed us to identify cold dust clumps linked to region B (that we have named the southern clump) and region C (clumps 1 and 2), and an elongated filament. Molecular gas was clearly detected linked to the southern clump and the filament. The velocity of the molecular gas is compatible with the location of the dense gas in the expanding envelope of RCW 78. We estimate dust temperatures and total masses for the dust condensations from the emissions at different wavelengths in the far-IR and from the molecular line using local thermodynamic equilibrium and the virial theorem. Masses obtained through different methods agree within a factor of 2-6. Color-color diagrams and spectral energy distribution analysis of young stellar objects (YSOs) confirmed the presence of intermediate and low-mass YSOs in the dust regions, indicating that moderate star formation is present. In particular, a cluster of IR sources was identified inside the southern clump. The IRAC image at 8 μm revealed the existence of an infrared dust bubble of 16′′ in radius probably linked to the O-type star HD 117797 located at 4 kpc. The distribution of the near-and mid-IR emission indicate that warm dust is associated with the bubble.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de RadioastronomíaInstituto de Astrofísica de La Plat

New giant H II regions in the southern sky

We present results of a search for giant H II regions in southern galaxies. Using high-resolution spectra, obtained with the Magellan Inamori Kyocera Echelle (MIKE) at the Las Campanas Magellan II telescope, we were able to resolve the emission-line profiles and determine the intrinsic velocity dispersion of the ionized gas. Out of four observed regions, selected from previous CCD narrow-band photometry, we detected three H II regions showing supersonic velocity dispersion, characteristic of giant H II regions, and their location in diagnostic diagrams suggests that a powerful starburst is the source of ionization energy.Facultad de Ciencias Astronómicas y Geofísica

High-resolution spectroscopy of the blue compact dwarf galaxy Haro 15 : I. Internal kinematics

Using echelle spectroscopy, obtained at Las Campanas Observatory, we present a detailed study of the internal kinematics of the nebular material in multiple knots of the blue compact dwarf galaxy Haro15. A detailed analysis of the complex emission-line profiles shows the presence of an underlying broad component in almost all knots, and the brightest star-forming region shows unmistakable signs for the presence of two distinct narrow kinematical components. We also study the information that our analysis provides regarding the motion of the individual knots in the Haro15 galaxy potential, confirming that they follow galactic rotation. Finally, we examine the relation between their velocity dispersion and luminosity, finding that almost all knots follow the relation for virialized systems. This holds for the strong narrow components identified in complex fits and for single profile fits, although the latter show a flatter slope. In agreement with previous findings, in this paper we show that the existence of multiple kinematical components among massive starbursts cannot be overlooked, as it has a noticeable effect on any subsequent analysis that relies on basic parameters.Facultad de Ciencias Astronómicas y Geofísica

Millimeter and far-IR study of the IRDC SDC 341.232-0.268

We analyze the molecular gas and dust associated with the infrared dark cloud SDC 341.232-0.268 in order to investigate the characteristics and parameters of the gas, determine the evolutionary status of four embedded EGO candidates and establish possible infall or outflow gas motions. We based our study on 12CO(2-1), 13 CO(2-1), and C18O(2-1) data obtained with the APEX telescope, molecular data of high density tracers from the MALT90 survey and IR images from Spitzer, Herschel and ATLASGAL. The study reveals two clumps at -44 km/s towards the IRDC, with  densities of > 10^4 cm-3 , typical of IRDCs, while high density tracers show H2 densities > 10^5 . FIR images reveals the presence of cold dust linked to the molecular clumps and EGOs. A comparison of spectra of the optically thin and optically thick molecular lines towards the EGOs suggests the existence of infall and outflow motions.Fil: Vazzano, María Mercedes. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Cappa, Cristina Elisabeth. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Firpo, Verónica. Universidad de La Serena; ChileFil: Lopez Carballo, C. H.. Universidad de La Serena; ChileFil: Rubio, Mónica. Universidad de Chile; ChileFil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentin

Chemodynamics on BCDs

This work presents a brief summary of the analysis we are performing on the physical and chemical properties of the ionizing gas in star-forming regions belonging to 2 Blue Compact Dwarf galaxies (BCDs), using high resolution echelle spectra. Our aim is to perform a detailed study of the Chemodinamics on BCDs galaxies. To do that, we use the LMFIT (python tool), Pyneb (Luridiana et al. 2015) and our own code (Hagele et al. 2008). We deconvolve the emission-line profiles fitting several gaussians to the different kinematical components to be able to estimate the properties and the nature of the ionized gas. Our next step is to use our kinematical information to performe the chemical abundance analysis and to infer the physical properties of the gas (the chemodynamical study) by using the metodology published in Hagele et al. (2012).Fil: Campuzano Castro, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hägele, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Bosch, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Firpo, Verónica. Universidad de La Serena; ChileFil: Morrell, Nidia Irene. Las Campanas Observatory; ChileFil: Cardaci, Monica Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFirst Workshop on Chemical Abundances in Gaseous NebulaeCampos do JordaoBrasilUniversidade do Vale do Paraíb

High-velocity blueshifted Fe II absorption in the dwarf star-forming galaxy PHL 293B: evidence for a wind driven supershell?

X-shooter and WHT-ISIS spectra of the star-forming galaxy PHL 293B also known as A2228- 00 and SDSS J223036.79-000636.9 are presented in this paper. We find broad (FWHM = 1000 km s-1) and very broad (FWZI = 4000 km s-1) components in the Balmer lines, narrow absorption components in the Balmer series blueshifted by 800 km s-1, previously undetected Fe II multiplet (42) absorptions also blueshifted by 800 km s-1, IR CaII triplet stellar absorptions consistent with [Fe/H] < -2.0 and no broad components or blueshifted absorptions in the He I lines. Based on historical records, we found no optical variability at the 5s level of 0.02 mag between 2005 and 2013 and no optical variability at the level of 0.1 mag for the past 24 yr. The lack of variability rules out transient phenomena like luminous blue variables or Type IIn supernovae as the origin of the blueshifted absorptions of HI and Fe II. The evidence points to either a young and dense expanding supershell or a stationary cooling wind, in both cases driven by the young cluster wind.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica