NGC 1549

{{Short description|Galaxy in the constellation Dorado}}

{{Infobox galaxy

| name = NGC 1549

| image = File:NGC 1549 NGC 1553 legacy dr10 bright.jpg

| caption = NGC 1549 (top) and NGC 1553 (bottom) by legacy surveys

| credit =

| epoch = J2000

| type = E0-1 {{cite web

| title=NASA/IPAC Extragalactic Database

| work=Results for NGC 1549

| url=http://ned.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC+1549

| access-date=2016-01-18 }}

| ra = {{RA|04|15|45.1}}

| dec = {{DEC|-55|35|32}}

| dist_ly = 51.2 ± 14 Mly (15.7 ± 4.4 Mpc)

| z = 0.004190 ± 0.000040

| h_radial_v = 1,256 ± 12 km/s

| appmag_v = 9.6

| size_v = 4.9{{prime}} × 4.1{{prime}}

| group_cluster = Dorado Group

| constellation name = Dorado

| notes =

| names = ESO 157-G16, AM 0414-554, PGC 14757}}

NGC 1549 is an elliptical galaxy located in the constellation Dorado. It is located at a distance of about 50 million light years from Earth, which, given its apparent dimensions, means that NGC 1549 is about 75,000 light years across. NGC 1549 was discovered by John Herschel on 6 December 1835 and may have been observed by James Dunlop in 1826.{{cite web |last1=Seligman |first1=Courtney |title=NGC 1549 (= PGC 14757) |url=https://cseligman.com/text/atlas/ngc15.htm#1549 |website=Celestial Atlas |access-date=19 November 2018}} It is a member of the Dorado Group.

In the centre of NGC 1549 is expected to lie a supermassive black hole, whose mass is estimated to be between 390 and 810 million (10^{{{val|8.76|+0.15|0.17}}}) {{solar mass|link=yes}} based on the Sérsic index of the galaxy.{{cite journal |last1=Mutlu-Pakdil |first1=Burçin |last2=Seigar |first2=Marc S. |last3=Davis |first3=Benjamin L. |title=The local black hole mass function derived from the MBH-P and the MBH-n relations |journal=The Astrophysical Journal |date=17 October 2016 |volume=830 |issue=2 |pages=117 |doi=10.3847/0004-637X/830/2/117|bibcode=2016ApJ...830..117M |arxiv=1607.07325 |s2cid=118586684 |doi-access=free }} No polycyclic aromatic hydrocarbons (PAHs) emission, an indicator for the presence of interstellar dust, was detected by the Infrared Spectrograph onboard Spitzer Space Telescope.{{cite journal |last1=Kaneda |first1=H. |last2=Onaka |first2=T. |last3=Sakon |first3=I. |last4=Kitayama |first4=T. |last5=Okada |first5=Y. |last6=Suzuki |first6=T. |title=Properties of Polycyclic Aromatic Hydrocarbons in Local Elliptical Galaxies Revealed by the Infrared Spectrograph on Spitzer |journal=The Astrophysical Journal |date=September 2008 |volume=684 |issue=1 |pages=270–281 |doi=10.1086/590243|bibcode=2008ApJ...684..270K |arxiv=0805.3257 |s2cid=14065147 }} NGC 1549 has been found to emit X-rays, with its total flux exceeding {{val|2|e=40}} ergs s–1 for the 0.3–5 keV band.{{cite journal |last1=Diehl |first1=Steven |last2=Statler |first2=Thomas S. |title=The Hot Interstellar Medium of Normal Elliptical Galaxies. I. A Chandra Gas Gallery and Comparison of X-Ray and Optical Morphology |journal=The Astrophysical Journal |date=10 October 2007 |volume=668 |issue=1 |pages=150–167 |doi=10.1086/521009|bibcode=2007ApJ...668..150D |arxiv=astro-ph/0606215 |s2cid=14507041 }} A total number of 150 globular clusters are estimated to exist in NGC 1549, a number low compared to similar size galaxies.{{cite journal |last1=Bridges |first1=Terry J. |last2=Hanes |first2=David A. |title=Globular clusters in the interacting galaxies NGC 1549 and NGC 1553 |journal=The Astronomical Journal |date=April 1990 |volume=99 |pages=1100 |doi=10.1086/115399|bibcode=1990AJ.....99.1100B }} The outer isophotes of the galaxy appear twisted and feature faint shells.{{cite journal |last1=Franx |first1=Marijn |last2=Illingworth |first2=Garth |last3=Heckman |first3=Timothy |title=Multicolor surface photometry of 17 ellipticals |journal=The Astronomical Journal |date=August 1989 |volume=98 |pages=538 |doi=10.1086/115157|bibcode=1989AJ.....98..538F |hdl=1887/6554 |url=https://openaccess.leidenuniv.nl/bitstream/handle/1887/6554/AJ_98_538_576.pdf?sequence=1 |hdl-access=free }}

NGC 1549 forms an interacting pair with the lenticular galaxy NGC 1553, which lies 12 arcminutes to the south.{{cite journal |author1=de Vaucouleurs, G. |author2=de Vaucouleurs, A. |author3=Corwin, J. R. |title=Second reference catalogue of bright galaxies |journal=Second Reference Catalogue of Bright Galaxies |volume=1976 |date=1976 |bibcode=1976RC2...C......0D}} It is the largest elliptical galaxy in a moderate size galaxy group known as the Dorado Group.{{cite journal |last1=Kilborn |first1=V. A. |last2=Koribalski |first2=B. S. |last3=Forbes |first3=D. A. |last4=Barnes |first4=D. G. |last5=Musgrave |first5=R. C. |title=A wide-field HI study of the NGC 1566 group |journal=Monthly Notices of the Royal Astronomical Society |date=1 January 2005 |volume=356 |issue=1 |pages=77–88 |doi=10.1111/j.1365-2966.2004.08450.x|doi-access=free |bibcode=2005MNRAS.356...77K |arxiv=astro-ph/0409743 }}