[Fe II] 1.644$\mu$m imaging survey of planetary nebulae with low-ionisation structures

Abstract

Low-ionisation structures (LISs) are commonly found in planetary nebulae (PNe) but they are still poorly understood. The recent discovery of unforeseen molecular hydrogen gas (H2) has changed what we think we know about these microstructures and PNe. For an overall understanding of LISs, an [Fe II] 1.644$\mu$m imagery survey in PNe with LISs was carried out with the aim to detect the [Fe II] 1.644$\mu$m emission line, a common tracer of shocks. We present the first detection of [Fe II] 1.644$\mu$m line directly associated with the LISs in four out of five PNe. The theoretical H I 12-4 recombination line is also computed either from the Br$\gamma$ or the H$\beta$ line and subtracted from the observed narrowband line fluxes. [Fe II] 1.644$\mu$m flux ranges from 1 to 40x10${}^{-15}$ ergs cm${}^{-2}$ s${}^{-1}$ and the surface brightness from 2 to 90x10${}^{-5}$ erg cm${}^{-2}$ s${}^{-1}$ sr${}^{-1}$. The R(Fe)=[Fe II] 1.644$\mu$m/Br$\gamma$ line ratio is also computed and varies between 0.5 and 7. In particular, the [Fe II] 1.644$\mu$m line is detected in NGC 6543 (R(Fe)<0.15), the outer pairs of LISs in NGC 7009 (R(Fe)<0.25), the jet-like LISs in IC 4634 (R(Fe)$\sim$1) and in several LISs in NGC 6571 (2<R(Fe)<7). The low R(Fe) in NGC 6543 is attributed to the UV radiation from the central star. Contrarily, the higher values in NGC 6571 and IC 4634 are indicative to shocks. The moderate R(Fe) in NGC 7009 likely indicates the contribution of both mechanisms.

arXiv comment13 pages, 9 figures, 6 tables, accepted for publication in A&A

References in corpus (77)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Young Planetary Nebulae: Hubble Space Telescope Imaging and a New Morphological Classification System
• Investigating the Near-Infrared Properties of Planetary Nebula II. Medium Resolution Spectra
• Low-ionization structures in planetary nebulae: confronting models with observations
• Grain size distributions and photo-electric heating in ionized media
• Revealing the Photodissociation Region: Hubble Space Telescope/NICMOS Imaging of NGC 7027
• HST Measurements of the Expansion of NGC 6543: Parallax Distance and Nebular Evolution
• New Galactic supernova remnants discovered with IPHAS
• Outflows from Evolved Stars: The Rapidly Changing Fingers of CRL618
• On expansion parallax distances for planetary nebulae
• A diagnostic tool for the identification of Supernova Remnants
• A multi-wavelength study of Supernova Remnants in six nearby galaxies. II. New optically selected Supernova Remnants
• The Near-Infrared Structure and Spectra of the Bipolar Nebulae M 2--9 and Afgl 2688: The Role of UV-Pumping and Shocks in Molecular Hydrogen Excitation
• Low-ionization structures in planetary nebulae - I: physical, kinematic and excitation properties
• Infrared [Fe II] Emission Lines from Radiative Atomic Shocks
• A morpho-kinematic and spectroscopic study of the bipolar nebulae: M 2-9, Mz 3, and Hen 2-104
• The Angular Expansion and Distance of the Planetary Nebula BD+30 3639
• Shaping Planetary Nebulae by Light Jets
• Photoevaporating flows from the cometary knots in the Helix nebula (NGC 7293)
• Multiple and Precessing Collimated Outflows in the Planetary Nebula IC 4634
• The physical parameters, excitation and chemistry of the rim, jets and knots of the planetary nebula NGC 7009
• Near Infrared Spectra of Compact Planetary Nebulae
• The 3-D ionization structure and evolution of NGC 7009 (Saturn Nebula)
• A Butterfly in the Making: Revealing the Near- Infrared Structure of Hubble 12
• H${}_2$ in low-ionization structures of planetary nebulae
• A Detailed Morpho-Kinematic Model of the Eskimo, NGC 2392. A Unifying View with the Cat's Eye and Saturn Planetary Nebulae
• M4-18: The planetary nebula and its WC10 central star
• A 3D Photoionization Model of the Extreme Planetary Nebula NGC 6302
• Unveiling shocks in planetary nebulae
• Models of the Mass-Ejection Histories of pre Planetary Nebulae, IV. Magnetized Winds and the Origins of Jets, Bullets, and FLIERs
• Discovery of an Apparent High Latitude Galactic Supernova Remnant
• Kinematics of Molecular Hydrogen Emission from Pre-planetary Nebulae: RAFGL 2688 and RAFGL 618
• Multiple Molecular H2 Outflows in AFGL 618
• Extended Structures of Planetary Nebulae Detected in H${}_2$ Emission
• Common Envelope Shaping of Planetary Nebulae. II. Magnetic Solutions and Self-Collimated Outflows
• A Survey of Irradiated Pillars, Globules, and Jets in the Carina Nebul
• Low-ionization pairs of knots in planetary nebulae: physical properties and excitation
• AGB winds in interacting binary stars
• The planetary nebula IC 4776 and its post-common-envelope binary central star
• Space Velocity and Time Span of Jets in Planetary Nebulae
• K 4-47: a planetary nebula excited by photons and shocks
• Kinematic Structure of H2 and [Fe II] in the Bipolar Planetary Nebula M 2-9
• Evidence for a [WR] or WEL-type binary nucleus in the bipolar planetary nebula Vy 1-2
• An Imaging Spectroscopic Survey of the Planetary Nebula NGC 7009 with MUSE
• H2 infrared line emission from the ionized region of planetary nebulae
• Tomography of the unique on-going jet in the planetary nebula NGC 2392
• Exploring the differences of integrated and spatially resolved analysis using integral field unit data: The case of Abell 14
• High velocity string of knots in the outburst of the Planetary Nebula Hb4
• Modeling the physical and excitation conditions of the molecular envelope of NGC 7027
• H${}_2$ emission in the low-ionisation structures of the Planetary Nebulae NGC 7009 and NGC 6543
• "Distance mapping" and the 3-D structure of BB +30 3639
• 3-D modelling of the collimated bipolar outflows of compact planetary nebulae with WR-type central stars
• Panchromatic HST/WFC3 Imaging Studies of Young, Rapidly Evolving Planetary Nebulae. II. NGC 7027
• IFU spectroscopy of Southern Planetary Nebulae V: Low-ionization structures
• The formation of `columns crowns' by jets interacting with a circumstellar dense shell
• High-speed knots in the hourglass shaped planetary nebula Hubble 12
• Shaping planetary nebulae with jets in inclined triple stellar systems
• Dissecting the X-ray Emission in the Young Planetary Nebula NGC 7027
• Panchromatic HST/WFC3 Imaging Studies of Young, Rapidly Evolving Planetary Nebulae. I. NGC 6302
• The excitation mechanism of H2 in bipolar planetary nebulae
• Spectroscopic Analysis Tool for intEgraL fieLd unIt daTacubEs (satellite): Case studies of NGC 7009 and NGC 6778 with MUSE
• Distance mapping applied to four well-known planetary nebulae and a nova shell
• Kinematical Investigation of Possible Fast Collimated Outflows in Twelve Planetary Nebulae
• Models of the Mass-Ejection Histories of pre Planetary Nebulae. II. The Formation of the Butterfly and its Proboscis in M2-9
• Proper Motion and Kinematics of the Ansae in NGC7009
• Photoevaporation of Molecular Clouds in Regions of Massive Star Formation as Revealed Through H${}_2$ and Br$\gamma$ Emission
• Low-ionization structures in planetary nebulae -- III. The statistical analysis of physico-chemical parameters and excitation mechanisms
• Shaping `Ears' in planetary nebulae by early jets
• Low-ionization structures in planetary nebulae -- II. Densities, temperatures, abundances and excitation of 6 PNe
• Catching a Grown-Up Starfish Planetary Nebula: I. Morpho-Kinematical study of PC 22
• Numerical simulations of wind-driven protoplanetary nebulae. I. near-infrared emission
• History of the mass ejection in K 4-37: from the AGB to the evolved planetary nebula phase
• The [S II] Spectral Images of the Planetary Nebula NGC 7009: II. Major Axis
• The Effect of the Slit Configuration on the H${}_2$ 1-0~S(1) to Br$\gamma$ Line Ratio of Spatially Resolved Planetary Nebulae