&lt;title&gt;Bolometer array development at the Max-Planck-Institut fuer Radioastronomie&lt;/title&gt;

Kreysa, E.; Gemuend, H. P.; Gromke, J.; Haslam, C. G. T.; Reichertz, L. A.; Häller, E. E.; Beeman, J. W.; Hansen, V.; Sievers, A.; Zylka, R.

doi:10.1117/12.317367

Cited by 131 publications

(46 citation statements)

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“…Our sample is complete for these criteria over 0.5 deg 2 . This area includes the "LockmanNorth" field observed with the VLA (Owen & Morrison 2008;Owen et al 2009) and Herschel (Oliver et al 2010 (Kreysa et al 1998). 62% (10/16) of our sources are detected with S /N > 3 at 1.2 mm (Table 1) and are thus submillimeter galaxies (SMGs) with S 1.2 mm > 2 mJy ( S 1.2 mm = 2.72±0.54 mJy).…”

Section: Sample Selectionmentioning

confidence: 99%

Mid-infrared spectroscopy ofSpitzer-selected ultra-luminous starbursts atz ~ 2

Fiolet

Omont

Lagache

et al. 2010

A&A

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Context. Spitzer's wide-field surveys and followup capabilities have allowed a new breakthrough in mid-IR spectroscopy up to redshifts ≥2, especially for 24 μm detected sources. Aims. We want to study the mid-infrared properties and the starburst and AGN contributions, of 24 μm sources at z ∼ 2, through analysis of mid-infrared spectra combined with millimeter, radio, and infrared photometry. Mid-infrared spectroscopy allows us to recover accurate redshifts. Methods. A complete sample of 16 Spitzer-selected sources (ULIRGs) believed to be starbursts at z ∼ 2 ("5.8 μm-peakers") was selected in the (0.5 deg 2 ) J1064+56 SWIRE Lockman Hole field ("Lockman-North"). These sources have S 24 μm > 0.5 mJy, a stellar emission peak redshifted to 5.8 μm, and r Vega > 23. The entire sample was observed with the low resolution units of the Spitzer/IRS infrared spectrograph. These sources have 1.2 mm observations with IRAM 30 m/MAMBO and very deep 20 cm observations from the VLA. Nine of our sources also benefit from 350 μm observation and detection from CSO/SHARC-II. All these data were jointly analyzed.Results. The entire sample shows good quality IRS spectra dominated by strong PAH features. The main PAH features at 6.2, 7.7, 8.6, and 11.3 μm have high S /N average luminosities of 2.90 ± 0.31, 10.38 ± 1.09, 3.62 ± 0.27, and 2.29 ± 0.26 × 10 10 L , respectively. Thanks to their PAH spectra, we derived accurate redshifts spanning from 1.750 to 2.284. The average of these redshifts is 2.017 ± 0.038. This result confirms that the selection criteria of "5.8 μm-peakers" associated with a strong detection at 24 μm are reliable to select sources at z ∼ 2. We have analyzed the different correlations between PAH emission and infrared, millimeter, and radio emissions. Practically all our sources are strongly dominated by starburst emission, with only one source showing an important AGN contribution. We have also defined two subsamples based on the equivalent width at 7.7 μm to investigate AGN contributions. Conclusions. Our sample contains strong starbursts and represents a particularly 24 μm-bright class of SMGs. The very good correlation between PAH and far-IR luminosities is now confirmed in high-z starburst ULIRGs. These sources show a small AGN contribution to the mid-IR, around ∼20% or less in most cases.

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Section: Sample Selectionmentioning

confidence: 99%

Mid-infrared spectroscopy ofSpitzer-selected ultra-luminous starbursts atz ~ 2

Fiolet

Omont

Lagache

et al. 2010

A&A

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“…The passband of the MPIfR bolometers has an equivalent width of ≈ 70 GHz and is centered at ν eff ≈ 240 GHz (Kreysa et al 1998). The MAMBO (37 channels) camera was used in February-April 1999, January-March 2000, and December 2000-May 2001 for a total integration time of ∼ 30 hours.…”

Section: Dust Continuum Observations At 12 MMmentioning

confidence: 99%

The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X

Motte

Bontemps

Schilke

et al. 2007

A&A

327

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Aims. Our current knowledge of high-mass star formation is mainly based on follow-up studies of bright sources found by IRAS, and is thus biased against its earliest phases, inconspicuous at infrared wavelengths. We therefore started searching, in an unbiased way and in the closest high-mass star-forming complexes, for the high-mass analogs of low-mass pre-stellar cores and class 0 protostars. Methods. We have made an extensive 1.2 mm continuum mosaicing study of the Cygnus X molecular cloud complex using the MAMBO cameras at the IRAM 30 m telescope. The ∼ 3 • 2 imaged areas cover all the high-column density (A V ≥ 15 mag) clouds of this nearby (∼ 1.7 kpc) cloud complex actively forming OB stars. We then compared our millimeter maps with mid-infrared images, and have made SiO(2-1) follow-up observations of the best candidate progenitors of high-mass stars. Results. Our complete study of Cygnus X with ∼ 0.09 pc resolution provides, for the first time, an unbiased census of massive young stellar objects. We discover 129 massive dense cores (FWHM size ∼ 0.1 pc, M 1.2 mm = 4 − 950 M ⊙ , volume-averaged density ∼ 10 5 cm −3 ), among which ∼ 42 are probable precursors of high-mass stars. A large fraction of the Cygnus X dense cores (2/3 of the sample) remain undetected by the MSX satellite, regardless of the mass range considered. Among the most massive (> 40 M ⊙ ) cores, infrared-quiet objects are driving powerful outflows traced by SiO emission. Our study qualifies 17 cores as good candidates for hosting massive infrared-quiet protostars, while up to 25 cores potentially host high-luminosity infrared protostars. We fail to discover in the high-mass analogs of pre-stellar dense cores (∼ 0.1 pc, > 10 4 cm −3 ) in Cygnus X, but find several massive starless clumps (∼ 0.8 pc, 7 × 10 3 cm −3 ) that might be gravitationally bound. Conclusions. Since our sample is derived from a single molecular complex and covers every embedded phase of high-mass star formation, it gives the first statistical estimates of their lifetime. In contrast to what is found for low-mass class 0 and class I phases, the infrared-quiet protostellar phase of high-mass stars may last as long as their better-known high-luminosity infrared phase. The statistical lifetimes of high-mass protostars and pre-stellar cores (∼ 3 × 10 4 yr and < 10 3 yr) in Cygnus X are one and two order(s) of magnitude smaller, respectively, than what is found in nearby, low-mass star-forming regions. We therefore propose that high-mass pre-stellar and protostellar cores are in a highly dynamic state, as expected in a molecular cloud where turbulent processes dominate.

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“…117 element MAMBO-II bolometer camera (Kreysa et al 1998) at the IRAM 30-m telescope. Each source was mapped using the standard on-the-fly technique such that a ∼2 region was uniformly sampled (although the actual extents of the maps are considerably larger).…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Spectral energy distributions of 6.7 GHz methanol masers

Pandian

Momjian

et al. 2010

A&A

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Context. The 6.7 GHz maser transition of methanol has been found exclusively towards massive star forming regions. A majority of the masers have been found to lack the presence of any associated radio continuum. This could be due to the maser emission originating prior to the formation of an H ii region around the central star, or from the central object being too cool to produce a H ii region.Aims. One way to distinguish between the two scenarios is to determine and model the spectral energy distributions (SEDs) of the masers. Methods. We observed a sample of 20 6.7 GHz methanol masers selected from the blind Arecibo survey, from centimeter to submillimeter wavelengths. We combined our observations with existing data from various Galactic plane surveys to determine SEDs from centimeter to near-infrared wavelengths. Results. We find that 70% of the masers do not have any associated radio continuum, with the rest of the sources being associated with hypercompact and ultracompact H ii regions. Modeling the SEDs shows them to be consistent with rapidly accreting massive stars, with accretion rates well above 10 −3 M yr −1 . The upper limits on the radio continuum are also consistent with any ionized region being confined close to the stellar surface. Conclusions. This confirms the paradigm of 6.7 GHz methanol masers being signposts of early phases of massive star formation, mostly prior to the formation of a hypercompact H ii region.

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<title>Bolometer array development at the Max-Planck-Institut fuer Radioastronomie</title>

Cited by 131 publications

References 0 publications

Mid-infrared spectroscopy ofSpitzer-selected ultra-luminous starbursts atz ~ 2

Mid-infrared spectroscopy ofSpitzer-selected ultra-luminous starbursts atz ~ 2

The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X

Spectral energy distributions of 6.7 GHz methanol masers

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