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Oliva, Ma. Guadalupe; Lugo, Alfonso; Alcocer, Javier; Peralta, Laura; Sánchez, Mario Alberto Morales

doi:10.1023/a:1014578024049

Cited by 51 publications

(16 citation statements)

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“…The resulting spectrum is multiplied by a solar spectrum to correct for the standard star absorption features. The wavelength calibration used OH sky lines from the list in Oliva & Origlia (1992).…”

Section: K-band Spectroscopymentioning

confidence: 99%

Extreme Star Formation in the Interacting Galaxy Arp 299 (IC 694 + NGC 3690)

Alonso‐Herrero

Rieke

et al. 2000

ApJ

121

199

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We present a comprehensive study of the star-formation properties of the infrared luminous galaxy Arp 299 (IC 694 + NGC 3690). The observations include HST/NICMOS imaging and MMT optical and near-infrared spectroscopy together with HST archival data. We correct the galaxy parameters for extinction and use the results as boundary conditions for evolutionary starburst models.These models and other arguments show that Arp 299 has been going through a broad variety of interaction-induced star formation for the last ∼ 15 Myr. In addition to nuclear starbursts in the two colliding galaxies, there are nearby luminous star forming regions that may be the result of molecular clouds breaking up and starting to form massive stars as they approach the nuclear potential. Two regions near the interaction region have very recently formed massive stars (∼ 4 Myr old). One of these regions in particular appears to have undergone a starburst of very short duration, in contrast with the 5-10 Myr durations that are typical of nuclear events. These regions will probably form gravitationally bound new dwarf galaxies, although they are close enough to the more massive original galaxies that they will probably eventually be subsumed into them. In addition, we find 19 H ii regions at least as energetic as 30 Doradus, and 21 older star clusters that likely are the products of similar H ii regions formed in the past. This population of supergiant H ii regions is unprecedented in normal galaxies and emphasizes that the effects of the interaction propagate through the entire pair of galaxies.

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Section: K-band Spectroscopymentioning

confidence: 99%

Extreme Star Formation in the Interacting Galaxy Arp 299 (IC 694 + NGC 3690)

Alonso‐Herrero

Rieke

et al. 2000

ApJ

121

199

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“…The data were wavelength calibrated using sky lines (for H 2 , four bright lines occupy the passband of the echelle at 2.122 mm; Davis et al 2000) or a combination of sky and argon arc lines (both were needed to calibrate the Brg data): we used the OH calibrations of Oliva & Origlia (1992). The IRAF tasks used to accomplish this (IDENTIFY, RE-IDENTIFY, FITCOORDS and TRANSFORM) also corrects for distortion along the columns in each image (i.e.…”

Section: O B S E Rvat I O N Smentioning

confidence: 99%

Near-infrared echelle spectroscopy of Class I protostars: molecular hydrogen emission-line (MHEL) regions revealed

Davis

Ray

Desroches

et al. 2001

Monthly Notices of the Royal Astronomical Society

115

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Infrared echelle spectra are used to trace dynamic activity in the immediate vicinity of Class I outflow sources. The H 2 and Brγ observations presented here trace different components of these emission‐line regions; indeed, they are thought to trace the orthogonal processes of outflow and infall respectively. High‐velocity H 2 emission is detected in the extended lobes of nine outflows. In addition, complex H 2 line emission is observed within a few hundred au of nine of the outflow sources. We refer to these H 2 emission regions as ‘molecular hydrogen emission‐line’ regions, or MHELs, and compare their properties to those of forbidden emission‐line regions (FELs) observed in classical T Tauri and some Herbig AeBe stars. Like the FELs, both low‐ and high‐velocity components (LVCs and HVCs) are observed in H 2, with blueshifted velocities of the order of 5–20 and 50–150 km s−1 respectively. LVCs are more common than HVCs in MHEL regions, and like their FEL counterparts, the latter are spatially further offset from the exciting source in each case. The MHEL regions – which are in all cases preferentially blueshifted – are assumed to be associated with the base of each outflow. Brγ profiles are detected towards four of the Class I sources observed (SVS 13, IRAS 04239+2436, HH 34‐IRS and GGD 27(1)) as well as towards the T Tauri star AS 353A. These lines are all broad and symmetric, the line peaks being blueshifted by ∼30 km s−1. The profiles are typical of the permitted hydrogen line profiles observed in many T Tauri stars, and probably derive from magnetospheric accretion flows. We do not observe redshifted absorption features (inverse P‐Cygni profiles) in any of the sources, however. Nor do we detect a dependence on linewidth with inclination angle of the system to the line of sight, as is predicted by such accretion models. No Brγ is detected in the extended flow lobes. Instead, the emission is confined to the source and is spatially unresolved along each flow axis.

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“…Dome flats, which were the difference of flats obtained with the dome lights on and with the lights off, were used to remove variations in the pixel-to-pixel sensitivity across the slit. The bright OH night sky lines (Oliva & Origlia 1992) were used to calculate the dispersion solution. We used the A0V atmospheric standards observed each night to place the counts in the J−, H−, and K−bands on a relative flux scale.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Near‐Infrared Spectroscopy of Molecular Hydrogen Emission in Four Reflection Nebulae: NGC 1333, NGC 2023, NGC 2068, and NGC 7023

Martini

Sellgren

DePoy

1999

ApJ

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We present near-infrared spectroscopy of fluorescent molecular hydrogen (H 2 ) emission from NGC 1333, NGC 2023, NGC 2068 and derive the physical properties of the molecular material in these reflection nebulae. Our observations of NGC 2023 and NGC 7023 and the physical parameters we derive for these nebulae are in good agreement with previous studies. Both NGC 1333 and NGC 2068 have no previously-published analysis of near-infrared spectra. Our study reveals that the rotational-vibrational states of molecular hydrogen in NGC 1333 are populated quite differently from NGC 2023 and NGC 7023. We determine that the relatively weak UV field illuminating NGC 1333 is the primary cause of the difference. Further, we find that the density of the emitting material in NGC 1333 is of much lower density, with n ∼ 10 2 − 10 4 cm −3 . NGC 2068 has molecular hydrogen line ratios more similar to those of NGC 7023 and NGC 2023. Our model fits to this nebula show that the bright, H 2 −emitting material may have a density as high as n ∼ 10 5 cm −3 , similar to what we find for NGC 2023 and NGC 7023.Our spectra of NGC 2023 and NGC 7023 show significant changes in both the near-infrared continuum and H 2 intensity along the slit and offsets between the peaks of the H 2 and continuum emission. We find that these brightness changes may correspond to real changes in the density and temperatures of the emitting region, although uncertainties in the total column of emitting material along a given line of sight complicates the interpretation. The spatial difference in the peak of the H 2 and near-infrared continuum peaks in NGC 2023 and NGC 7023 shows that the near-infrared continuum is due to a material which can survive closer to the star than H 2 can.

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Cited by 51 publications

References 0 publications

Extreme Star Formation in the Interacting Galaxy Arp 299 (IC 694 + NGC 3690)

Extreme Star Formation in the Interacting Galaxy Arp 299 (IC 694 + NGC 3690)

Near-infrared echelle spectroscopy of Class I protostars: molecular hydrogen emission-line (MHEL) regions revealed

Near‐Infrared Spectroscopy of Molecular Hydrogen Emission in Four Reflection Nebulae: NGC 1333, NGC 2023, NGC 2068, and NGC 7023

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