arXiv subjects

Jari Kotilainen

Publications and source records attributed to Jari Kotilainen.

At least 37 records · Page 2Linked to original sources

arXiv2020

The SOXS Data-Reduction Pipeline

The SOXS is a dual-arm spectrograph (UV-VIS & NIR) and AC due to mounted on the ESO 3.6m NTT in La Silla. Designed to simultaneously cover the optical and NIR wavelength range from 350-2050 nm, the instrument will be dedicated to the study of transient and variable events with many Target of Opportunity requests expected. The goal of the SOXS Data Reduction pipeline is to use calibration data to remove all instrument signatures from the SOXS scientific data frames for each of the supported instrument modes, convert this data into physical units and deliver them with their associated error bars to the ESO SAF as Phase 3 compliant science data products, all within 30 minutes. The primary reduced product will be a detrended, wavelength and flux calibrated, telluric corrected 1D spectrum with UV-VIS + NIR arms stitched together. The pipeline will also generate QC metrics to monitor telescope, instrument and detector health. The pipeline is written in Python 3 and has been built with an agile development philosophy that includes adaptive planning and evolutionary development. The pipeline is to be used by the SOXS consortium and the general user community that may want to perform tailored processing of SOXS data. Test driven development has been used throughout the build using `extreme' mock data. We aim for the pipeline to be easy to install and extensively and clearly documented.

astro-ph.IM↗

arXiv2020

The AIV strategy of the Common Path of Son of X-Shooter

Son Of X-Shooter (SOXS) is a double-armed (UV-VIS, NIR) spectrograph designed to be mounted at the ESO-NTT in La Silla, now in its Assembly Integration and Verification (AIV) phase. The instrument is designed following a modular approach so that each sub-system can be integrated in parallel before their assembly at system level. INAF-Osservatorio Astronomico di Padova will deliver the Common Path (CP) sub-system, which represents the backbone of the entire instrument. In this paper, we describe the foreseen operation for the CP alignment and we report some results already achieved, showing that we envisaged the suitable setup and the strategy to meet the opto-mechanical requirements.

astro-ph.IM↗

arXiv2020

SOXS: Effects on optical performances due to gravity flexures, temperature variations, and subsystems alignment

SOXS (Son Of X-Shooter) is the new medium resolution wide-band spectrograph to be installed at the 3.6m New Technology Telescope (NTT) in La Silla. SOXS will offer simultaneous wavelength coverage from 0.35 to 2.0 μm and will be dedicated to the study of transient and variable sources. While nominal optical performances of the system were presented in previous proceedings (arXiv:1809.01521), we here present a set of further analyses aimed to identify and quantify optical effects, due to changes in temperature and orientation of the instrument during alignment and operations.

astro-ph.IM↗

arXiv2020

Progress on the UV-VIS arm of SOXS

We present our progress on the UV-VIS arm of Son Of X-Shooter (SOXS), a new spectrograph for the NTT. Our design splits the spectral band into four sub-bands that are imaged onto a single detector. Each band uses an optimized high efficiency grating that operates in 1st order (m=1). In our previous paper we presented the concept and preliminary design. SOXS passed a Final Design Review in July 2018 and is well into the construction phase. Here we present the final design, performances of key manufactured elements, and the progress in the assembly. Based on the as-built elements, the expected throughput of the visual arm will be >55%. This paper is accompanied by a series of contributions describing the progress made on the SOXS instrument.

astro-ph.IM↗

arXiv2020

Development status of the UV-VIS detector system of SOXS for the ESO-NTT telescope

SOXS will be the new spectroscopic facility for the ESO NTT telescope able to cover the optical and NIR bands by using two different arms: the UV-VIS (350-850 nm), and the NIR (800-2000 nm). In this article, we describe the development status of the visible camera cryostat, the architecture of the acquisition system and the progress in the electronic design. The UV-VIS detector system is based on a CCD detector 44-82 from e2v, a custom detector head, coupled with the ESO continuous flow cryostats (CFC), a custom cooling system, based on a Programmable Logic Controller (PLC), and the New General Controller (NGC) developed by ESO. This paper outlines the development status of the system, describes the design of the different parts that make up the UV-VIS arm and is accompanied by a series of information describing the SOXS design solutions in the mechanics and in the electronics parts. The first tests of the detector system with the UV-VIS camera will be shown.

astro-ph.IM↗

arXiv2020

Development status of the SOXS instrument control software

SOXS (Son Of X-Shooter) is a forthcoming instrument for ESO-NTT, mainly dedicated to the spectroscopic study of transient events and is currently starting the AIT (Assembly, Integration, and Test) phase. It foresees a visible spectrograph, a near-Infrared (NIR) spectrograph, and an acquisition camera for light imaging and secondary guiding. The optimal setup and the monitoring of SOXS are carried out with a set of software-controlled motorized components and sensors. The instrument control software (INS) also manages the observation and calibration procedures, as well as maintenance and self-test operations. The architecture of INS, based on the latest release of the VLT Software (VLT2019), has been frozen; the code development is in an advanced state for what concerns supported components and observation procedures, which run in simulation. In this proceeding we present the INS current status, focusing in particular on the ongoing efforts in the support of two non-standard, "special" devices. The first special device is the piezoelectric slit exchanger for the NIR spectrograph; the second special device is the piezoelectric tip-tilt corrector used for active compensation of mechanical flexures of the instrument.

astro-ph.IM↗

arXiv2020

Design and development of the SOXS calibration unit

SOXS is a new spectrograph for the New Technology Telescope (NTT), optimized for transient and variable objects, covering a wide wavelength range from 350 to 2000 nm. SOXS is equipped with a calibration unit that will be used to remove the instrument signatures and to provide wavelength calibration to the data. The calibration unit will employ seven calibration lamps: a quartz-tungsten-halogen and a deuterium lamp for the flat-field correction, a ThAr lamp and four pencil-style rare-gas lamps for the wavelength calibration. The light from the calibration lamps is injected into the spectrograph mimicking the f/11 input beam of the NTT, by using an integrating sphere and a custom doublet. The oversized illumination patch covers the length of the spectrograph slit homogeneously, with $< 1\%$ variation. The optics also supports the second mode of the unit, the star-simulator mode that emulates a point source by utilizing a pinhole mask. Switching between the direct illumination and pinhole modes is performed by a linear stage. A safety interlock switches off the main power when the lamp box cover is removed, preventing accidental UV exposure to the service personnel. All power supplies and control modules are located in an electronic rack at a distance from the telescope platform. In this presentation we describe the optical, mechanical, and electrical designs of the SOXS calibration unit, and report the status of development in which the unit is currently in the test and verification stage.

astro-ph.IM↗

arXiv2020

Star Formation in Luminous LoBAL Quasars at 2.0<z<2.5

Low-ionisation broad absorption line quasars (LoBALs) mark an important, yet poorly understood, population of quasars showing direct evidence for energetic mass outflows. We outline a sample of 12 luminous (L$_{\rm{bol}}$ $>$10$^{46}$ergs$^{-1}$) LoBALs at 2.0$<$z$<$2.5 - a key epoch in both star formation and black hole accretion, which have been imaged as part of a targeted program with the \textit{Herschel} Spectral and Photometric Imaging REceiver (SPIRE). We present K-band NOTCam spectra for three of these targets, calculating their spectroscopic redshifts, black hole masses and bolometric luminosities, and increasing the total number of LoBAL targets in our sample with spectral information from five to eight. Based on FIR obeservations from \textit{Herschel} SPIRE, we derive prolific SFRs ranging 740 - 2380M$_{\rm{\odot}}$yr$^{-1}$ for the detected targets, consistent with LoBALs existing in an evolutionary phase associated with starburst activity. Furthermore, an upper limit of $<$440M$_{\rm{\odot}}$yr$^{-1}$ is derived for the non-detections, meaning moderate-to-high SFRs cannot be ruled out, even among the undetected targets. Indeed, we detect an enhancement in both the SFRs and FIR fluxes of LoBALs compared to HiBAL and non-BAL quasars, further supporting the evolutionary LoBAL paradigm. Despite this enhancement in SFR however, the environments of LoBALs appear entirely consistent with the general galaxy population at 2.0$<$z$<$2.5.

astro-ph.GA↗

arXiv2020

Spectral properties of quasars from Sloan Digital Sky Survey data release 14: The catalog

We present measurements of the spectral properties for a total of 526,265 quasars, out of which 63% have continuum S/N$>3$ pixel$^{-1}$, selected from the fourteenth data release of the Sloan Digital Sky Survey (SDSS-DR14) quasar catalog. We performed a careful and homogeneous analysis of the SDSS spectra of these sources, to estimate the continuum and line properties of several emission lines such as H$α$, H$β$, H$γ$, Mg \textsc{ii}, C \textsc{iii]}, C \textsc{iv} and Ly$α$. From the derived emission line parameters, we estimated single-epoch virial black hole masses ($M_{\mathrm{BH}}$) for the sample using H$β$, Mg \textsc{ii} and C \textsc{iv} emission lines. The sample covers a wide range in bolometric luminosity ($\log L_{\mathrm{bol}}$; erg s$^{-1}$) between 44.4 and 47.3 and $\log M_{\mathrm{BH}}$ between 7.1 and 9.9 $M_{\odot}$. Using the ratio of $L_{\mathrm{bol}}$ to the Eddington luminosity as a measure of the accretion rate, the logarithm of the accretion rate is found to be in the range between $-$2.06 and 0.43. We performed several correlation analyses between different emission line parameters and found them to match with that known earlier using smaller samples. We noticed that strong Fe \textsc{ii} sources with large Balmer line width, and highly accreting sources with large $M_{\mathrm{BH}}$ are rare in our sample. We make available online an extended and complete catalog that contains various spectral properties of 526,265 quasars derived in this work along with other properties culled from the SDSS-DR14 quasar catalog.

astro-ph.GA↗

arXiv2019

The disc-like host galaxies of radio-loud Narrow-Line Seyfert 1s

Until recently, relativistic jets were ubiquitously found to be launched from giant elliptical galaxies. However, the detection by the Fermi-LAT of gamma-ray emission from radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxies raised doubts on this relation. Here, we morphologically characterize a sample of 29 RL-NLSy1s (including 12 gamma-ray emitters, gamma-NLSy1s) in order to find clues on the conditions needed by AGN to produce relativistic jets. We use deep near-infrared images from the Nordic Optical Telescope and the ESO VLT to analyze the surface brightness distribution of the galaxies in the sample. We detected 72% of the hosts (24% classified as gamma-NLSy1s). Although we cannot rule out that some RL-NLSy1s are hosted by dispersion supported systems, our findings strongly indicate that RL-NLSy1s hosts are preferentially disc galaxies. 52% of the resolved hosts (77% non-gamma-emitters and 20% gamma-emitters) show bars with morphological properties (long and weak) consistent with models that promote gas inflows, which might trigger nuclear activity. The extremely red bulges of the gamma-NLSy1s, and features that suggest minor mergers in 75% of their hosts might hint to the necessary conditions for gamma-rays to be produced. Among the features that suggest mergers in our sample, we find 6 galaxies that show offset stellar bulges with respect to their AGN. When we plot the nuclear versus the bulge magnitude, RL-NLSy1s locate in the low-luminosity end of flat-spectrum radio quasars (FSRQs), suggesting a similar accretion mode between these two AGN types.

astro-ph.GA↗

arXiv2018

MITS: the Multi-Imaging Transient Spectrograph for SOXS

The Son Of X-Shooter (SOXS) is a medium resolution spectrograph R~4500 proposed for the ESO 3.6 m NTT. We present the optical design of the UV-VIS arm of SOXS which employs high efficiency ion-etched gratings used in first order (m=1) as the main dispersers. The spectral band is split into four channels which are directed to individual gratings, and imaged simultaneously by a single three-element catadioptric camera. The expected throughput of our design is >60% including contingency. The SOXS collaboration expects first light in early 2021. This paper is one of several papers presented in these proceedings describing the full SOXS instrument.

astro-ph.IM↗

arXiv2018

The VIS detector system of SOXS

SOXS will be a unique spectroscopic facility for the ESO NTT telescope able to cover the optical and NIR bands thanks to two different arms: the UV-VIS (350-850 nm), and the NIR (800-1800 nm). In this article, we describe the design of the visible camera cryostat and the architecture of the acquisition system. The UV-VIS detector system is based on a e2v CCD 44-82, a custom detector head coupled with the ESO continuous ow cryostats (CFC) cooling system and the NGC CCD controller developed by ESO. This paper outlines the status of the system and describes the design of the different parts that made up the UV-VIS arm and is accompanied by a series of contributions describing the SOXS design solutions.

astro-ph.IM↗

arXiv2018

Architecture of the SOXS instrument control software

SOXS (Son Of X-Shooter) is a new spectrograph for the ESO NTT telescope, currently in the final design phase. The main instrument goal is to allow the characterization of transient sources based on alerts. It will cover from near-infrared to visible bands with a spectral resolution of $R \sim 4500$ using two separate, wavelength-optimized spectrographs. A visible camera, primarily intended for target acquisition and secondary guiding, will also provide a scientific "light" imaging mode. In this paper we present the current status of the design of the SOXS instrument control software, which is in charge of controlling all instrument functions and detectors, coordinating the execution of exposures, and implementing all observation, calibration and maintenance procedures. Given the extensive experience of the SOXS consortium in the development of instruments for the VLT, we decided to base the design of the Control System on the same standards, both for hardware and software control. We illustrate the control network, the instrument functions and detectors to be controlled, the overall design of SOXS Instrument Software (INS) and its main components. Then, we provide details about the control software for the most SOXS-specific features: control of the COTS-based imaging camera, the flexures compensation system and secondary guiding.

astro-ph.IM↗

arXiv2018

Optical design of the SOXS spectrograph for ESO NTT

An overview of the optical design for the SOXS spectrograph is presented. SOXS (Son Of X-Shooter) is the new wideband, medium resolution (R>4500) spectrograph for the ESO 3.58m NTT telescope expected to start observations in 2021 at La Silla. The spectroscopic capabilities of SOXS are assured by two different arms. The UV-VIS (350-850 nm) arm is based on a novel concept that adopts the use of 4 ion-etched high efficiency transmission gratings. The NIR (800- 2000 nm) arm adopts the '4C' design (Collimator Correction of Camera Chromatism) successfully applied in X-Shooter. Other optical sub-systems are the imaging Acquisition Camera, the Calibration Unit and a pre-slit Common Path. We describe the optical design of the five sub-systems and report their performance in terms of spectral format, throughput and optical quality. This work is part of a series of contributions describing the SOXS design and properties as it is about to face the Final Design Review.

astro-ph.IM↗

arXiv2018

The ELT-MOS (MOSAIC): towards the construction phase

When combined with the huge collecting area of the ELT, MOSAIC will be the most effective and flexible Multi-Object Spectrograph (MOS) facility in the world, having both a high multiplex and a multi-Integral Field Unit (Multi-IFU) capability. It will be the fastest way to spectroscopically follow-up the faintest sources, probing the reionisation epoch, as well as evaluating the evolution of the dwarf mass function over most of the age of the Universe. MOSAIC will be world-leading in generating an inventory of both the dark matter (from realistic rotation curves with MOAO fed NIR IFUs) and the cool to warm-hot gas phases in z=3.5 galactic haloes (with visible wavelenth IFUs). Galactic archaeology and the first massive black holes are additional targets for which MOSAIC will also be revolutionary. MOAO and accurate sky subtraction with fibres have now been demonstrated on sky, removing all low Technical Readiness Level (TRL) items from the instrument. A prompt implementation of MOSAIC is feasible, and indeed could increase the robustness and reduce risk on the ELT, since it does not require diffraction limited adaptive optics performance. Science programmes and survey strategies are currently being investigated by the Consortium, which is also hoping to welcome a few new partners in the next two years.

astro-ph.IM↗

arXiv2017

Near-IR spectroscopy of luminous LoBAL quasars at 1<z<2.5

We present near-IR spectroscopy of 22 luminous low-ionization broad absorption line quasars (LoBAL QSOs) at redshift 1.3 1 there is no clear difference in their optical emission line properties. We do not see particularly weak [OIII] or strong FeII emission. The LoBAL QSOs do not show a stronger prevalence of ionized gas outflows as traced by the [OIII] line, compared to normal QSOs of similar luminosity. We conclude that the optical-MIR properties of LoBAL QSOs are consistent with the general quasar population and do not support them to constitute a special phase of active galactic nucleus evolution.

astro-ph.GA↗

arXiv2014

The black hole - host galaxy relation for very low-mass quasars

Recently, the relation between the masses of the black hole ($M_{BH}$) and the host galaxy ($M_{host}$) in quasars has been probed down to the parameter space of $M_{BH}\sim10^8 M_\odot$ and $M_{host}\sim10^{11} M_\odot$ at z $<$ 0.5. In this study, we have investigated the $M_{BH}$ - $M_{host}$ log-linear relation for a sample of 37 quasars with low black hole masses ($10^7 M_\odot < M_{BH} < 10^{8.3} M_\odot$) at 0.5 $<$ z $<$ 1.0. The black hole masses were derived using virial mass estimates from SDSS optical spectra. For 25 quasars, we detected the presence of the host galaxy from deep near-infrared H-band imaging, whereas upper limits for the host galaxy luminosity (mass) were estimated for the 12 unresolved quasars. We combined our previous studies with the results from this work to create a sample of 89 quasars at z $<$ 1.0 having a large range of black hole masses ($10^7 M_\odot < M_{BH} < 10^{10} M_\odot$) and host galaxy masses ($10^{10} M_\odot < M_{host} < 10^{13} M_\odot$). Most of the quasars at the low mass end lie below the extrapolation of the local relation. This apparent break in the linearity of the entire sample is due to increasing fraction of disc-dominated host galaxies in the low-mass quasars. After correcting for the disc component, and considering only the bulge component, the bilinear regression for the entire quasar sample holds over 3.5 dex in both the black hole mass and the bulge mass, and is in very good agreement with the local relation. We advocate secular evolution of discs of galaxies being responsible for the relatively strong disc domination.

astro-ph.GA↗

arXiv2013

Near-infrared adaptive optics imaging of infrared luminous galaxies: the brightest cluster magnitude - star formation rate relation

We have established a relation between the brightest super star cluster magnitude in a galaxy and the host star formation rate (SFR) for the first time in the near infrared (NIR). The data come from a statistical sample of ~ 40 luminous IR galaxies (LIRGs) and starbursts utilizing K-band adaptive optics imaging. While expanding the observed relation to longer wavelengths, less affected by extinction effects, it also pushes to higher SFRs. The relation we find, M_K ~ - 2.6 log SFR, is similar to that derived previously in the optical and at lower SFRs. It does not, however, fit the optical relation with a single optical to NIR color conversion, suggesting systematic extinction and/or age effects. While the relation is broadly consistent with a size-of-sample explanation, we argue physical reasons for the relation are likely as well. In particular, the scatter in the relation is smaller than expected from pure random sampling strongly suggesting physical constraints. We also derive a quantifiable relation tying together cluster-internal effects and host SFR properties to possibly explain the observed brightest SSC magnitude vs. SFR dependency.

astro-ph.CO↗