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The Near-Infrared Spectrograph (NIRSpec) is one of the four focal plane instruments on the James Webb Space Telescope. In this paper, we summarize the in-orbit performance of NIRSpec, as derived from data collected during its commissioning campaign and the first few months of nominal science operations. More specifically, we discuss the performance of some critical hardware components such as the two NIRSpec Hawaii-2RG (H2RG) detectors, wheel mechanisms, and the micro-shutter array. We also summarize the accuracy of the two target acquisition procedures used to accurately place science targets into the slit apertures, discuss the current status of the spectro-photometric and wavelength calibration of NIRSpec spectra, and provide the as measured sensitivity in all NIRSpec science modes. Finally, we point out a few important considerations for the preparation of NIRSpec science programs., accepted by PASP for special issue on JWST in-orbit performance

Context. Ultraluminous infrared galaxies (ULIRGs) are characterised by extreme starburst (SB) and active galactic nucleus (AGN) activity, and are therefore ideal laboratories for studying the outflow phenomena and their feedback effects. We have recently started a project called Physics of ULIRGs with MUSE and ALMA (PUMA), which is a survey of 25 nearby (z) and neutral (Na ID) gas.Results. We show that the morphological and stellar kinematic classifications are consistent: post-coalescence systems are more likely associated with ordered motions, while interacting (binary) systems are dominated by non-ordered and streaming motions. We also find broad and asymmetric [O III] and Na ID profiles in almost all nuclear spectra, with line widths in the range [300-2000] km s(-1), possibly associated with AGN- and SB-driven winds. This result reinforces previous findings that indicated that outflows are ubiquitous during the pre- and post-coalescence phases of major mergers. © ESO 2021., We thank the referee for an expert review of our paper. The authors thanks Elena Valenti for her support when preparing the observations, and G. Vietri for useful discussion on spectral analysis of type 1 AGN. M. P. is supported by the Programa Atraccion de Talento de la Comunidad de Madrid via grant 2018-T2/TIC-11715. M. P., S. A., C. T. C. and L. C. acknowledge support from the Spanish Ministerio de Economia y Competitividad through the Grant ESP2017-83197-P, and PID2019-106280GB-I00. MPS acknowledges support from the Comunidad de Madrid through the Atraccion de Talento Investigador Grant 2018-T1/TIC-11035 and PID2019-105423GA-I00 (MCIU/AEI/FEDER,UE). EB acknowledges support from Comunidad de Madrid through the Attraccion de Talento grant 2017-T1/TIC-5213. S. C. acknowledge financial support from the State cf the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). A. C. G. acknowledges support from the Spanish Ministerio de Economia y Competitividad through the grant BES-2016-078214. RM acknowledges ERC Advanced Grant 695671 "QUENCH" and support by the Science and Technology Facilities Council (STFC). J. P. L. acknowledges financial support by the Spanish MICINN under Grant AYA2017-85170-R.

In this work we use seeing-limited SINFONI H- and K-band spectroscopy to analyse the spatially resolved kinematics of the stellar component in the inner r, Comment: 36 pages, 35, accepted for publication in A&A. Abstract abridged due to arXiv requirements

Context. Arp220 is the nearest and prototypical ultra-luminous infrared galaxy; it shows evidence of pc-scale molecular outflows in its nuclear regions and strongly perturbed ionised gas kinematics on kpc scales. It is therefore an ideal system for investigating outflow mechanisms and feedback phenomena in detail. Aims. We investigate the feedback effects on the Arp220 interstellar medium (ISM), deriving a detailed picture of the atomic gas in terms of physical and kinematic properties, with a spatial resolution that had never before been obtained (0.56″, i.e. ∼210 pc). Methods. We use optical integral-field spectroscopic observations from VLT/MUSE-AO to obtain spatially resolved stellar and gas kinematics, for both ionised ([N II]λ6583) and neutral (Na IDλλ589196) components; we also derive dust attenuation, electron density, ionisation conditions, and hydrogen column density maps to characterise the ISM properties. Results. Arp220 kinematics reveal the presence of a disturbed kpc-scale disc in the innermost nuclear regions as well as highly perturbed multi-phase (neutral and ionised) gas along the minor axis of the disc, which we interpret as a galactic-scale outflow emerging from the Arp220 eastern nucleus. This outflow involves velocities up to ∼1000 km s-1 at galactocentric distances of ≈5 kpc; it has a mass rate of ∼50 M- yr-1 and kinetic and momentum power of ∼1043 erg s-1 and ∼1035 dyne, respectively. The inferred energetics do not allow us to distinguish the origin of the outflows, namely whether they are active galactic nucleus- or starburst-driven. We also present evidence for enhanced star formation at the edges of - and within - the outflow, with a star-formation rate SFR ∼5 M- yr-1 (i.e. ∼2% of the total SFR). Conclusions. Our findings suggest the presence of powerful winds in Arp220: They might be capable of heating or removing large amounts of gas from the host ("negative feedback") but could also be responsible for triggering star formation ("positive feedback"). © ESO 2020., MP is supported by the Programa Atraccion de Talento de la Comunidad de Madrid via grant 2018-T2/TIC-11715. MP, SA, CTC and LC acknowledge support from the Spanish Ministerio de Economia y Competitividad through the grant ESP201783197-P, and PID2019-106280GB-I00. MPS acknowledges support from the Comunidad de Madrid through the Atraccion de Talento Investigador Grant 2018-T1/TIC-11035. SC acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). AF and RM acknowledge ERC Advanced Grant 695671 "QUENCH" and support by the Science and Technology Facilities Council (STFC). EB acknowledges the support from Comunidad de Madrid through the Atraccion de Talento grant 2017-T1/TIC-5213. JPL acknowledges financial support by the Spanish MICINN under grant AYA2017-85170-R. This paper makes use of data from the ESO Multi Unit Spectroscopic Explorer (MUSE) observing programme 0103.B-0391(A), available for download from the ESO archives: https://archive.eso.org/eso/eso_archive_main.html, for raw data, and http://archive.eso.org/wdb/wdb/adp/phase3_main/form, for reduced data.

We describe techniques concerning wavelength calibration and sky subtraction to maximise the scientific utility of data from tunable filter instruments. While we specifically address data from the Optical System for Imaging and low Resolution Integrated Spectroscopy instrument (OSIRIS) on the 10.4~m Gran Telescopio Canarias telescope, our discussion is generalisable to data from other tunable filter instruments. A key aspect of our methodology is a coordinate transformation to polar coordinates, which simplifies matters when the tunable filter data is circularly symmetric around the optical centre. First, we present a method for rectifying inaccuracies in the wavelength calibration using OH sky emission rings. Using this technique, we improve the absolute wavelength calibration from an accuracy of 5 Angstroms to 1 Angstrom, equivalent to ~7% of our instrumental resolution, for 95% of our data. Then, we discuss a new way to estimate the background sky emission by median filtering in polar coordinates. This method suppresses contributions to the sky background from the outer envelopes of distant galaxies, maximising the fluxes of sources measured in the corresponding sky-subtracted images. We demonstrate for data tuned to a central wavelength of 7615~$\rm\AA$ that galaxy fluxes in the new sky-subtracted image are ~37% higher, versus a sky-subtracted image from existing methods for OSIRIS tunable filter data., Comment: MNRAS accepted; 7 pages, 6 figures